Add m-esr52 at 52.6.0

10 files changed, 3353 insertions, 0 deletions

diff --git a/mozglue/misc/StackWalk.cpp b/mozglue/misc/StackWalk.cpp
new file mode 100644
index 000000000..bb23b922a
--- /dev/null
+++ b/mozglue/misc/StackWalk.cpp
@@ -0,0 +1,1204 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* API for getting a stack trace of the C/C++ stack on the current thread */
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/IntegerPrintfMacros.h"
+#include "mozilla/StackWalk.h"
+
+#include <string.h>
+
+using namespace mozilla;
+
+// The presence of this address is the stack must stop the stack walk. If
+// there is no such address, the structure will be {nullptr, true}.
+struct CriticalAddress
+{
+  void* mAddr;
+  bool mInit;
+};
+static CriticalAddress gCriticalAddress;
+
+// for _Unwind_Backtrace from libcxxrt or libunwind
+// cxxabi.h from libcxxrt implicitly includes unwind.h first
+#if defined(HAVE__UNWIND_BACKTRACE) && !defined(_GNU_SOURCE)
+#define _GNU_SOURCE
+#endif
+
+#if defined(HAVE_DLOPEN) || defined(XP_DARWIN)
+#include <dlfcn.h>
+#endif
+
+#if (defined(XP_DARWIN) && \
+     (defined(__i386) || defined(__ppc__) || defined(HAVE__UNWIND_BACKTRACE)))
+#define MOZ_STACKWALK_SUPPORTS_MACOSX 1
+#else
+#define MOZ_STACKWALK_SUPPORTS_MACOSX 0
+#endif
+
+#if (defined(linux) && \
+     ((defined(__GNUC__) && (defined(__i386) || defined(PPC))) || \
+      defined(HAVE__UNWIND_BACKTRACE)))
+#define MOZ_STACKWALK_SUPPORTS_LINUX 1
+#else
+#define MOZ_STACKWALK_SUPPORTS_LINUX 0
+#endif
+
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1)
+#define HAVE___LIBC_STACK_END 1
+#else
+#define HAVE___LIBC_STACK_END 0
+#endif
+
+#if HAVE___LIBC_STACK_END
+extern MOZ_EXPORT void* __libc_stack_end; // from ld-linux.so
+#endif
+
+#ifdef ANDROID
+#include <algorithm>
+#include <unistd.h>
+#include <pthread.h>
+#endif
+
+#if MOZ_STACKWALK_SUPPORTS_MACOSX
+#include <pthread.h>
+#include <sys/errno.h>
+#ifdef MOZ_WIDGET_COCOA
+#include <CoreServices/CoreServices.h>
+#endif
+
+typedef void
+malloc_logger_t(uint32_t aType,
+                uintptr_t aArg1, uintptr_t aArg2, uintptr_t aArg3,
+                uintptr_t aResult, uint32_t aNumHotFramesToSkip);
+extern malloc_logger_t* malloc_logger;
+
+static void
+stack_callback(uint32_t aFrameNumber, void* aPc, void* aSp, void* aClosure)
+{
+  const char* name = static_cast<char*>(aClosure);
+  Dl_info info;
+
+  // On Leopard dladdr returns the wrong value for "new_sem_from_pool". The
+  // stack shows up as having two pthread_cond_wait$UNIX2003 frames. The
+  // correct one is the first that we find on our way up, so the
+  // following check for gCriticalAddress.mAddr is critical.
+  if (gCriticalAddress.mAddr || dladdr(aPc, &info) == 0  ||
+      !info.dli_sname || strcmp(info.dli_sname, name) != 0) {
+    return;
+  }
+  gCriticalAddress.mAddr = aPc;
+}
+
+static void
+my_malloc_logger(uint32_t aType,
+                 uintptr_t aArg1, uintptr_t aArg2, uintptr_t aArg3,
+                 uintptr_t aResult, uint32_t aNumHotFramesToSkip)
+{
+  static bool once = false;
+  if (once) {
+    return;
+  }
+  once = true;
+
+  // On Leopard dladdr returns the wrong value for "new_sem_from_pool". The
+  // stack shows up as having two pthread_cond_wait$UNIX2003 frames.
+  const char* name = "new_sem_from_pool";
+  MozStackWalk(stack_callback, /* skipFrames */ 0, /* maxFrames */ 0,
+               const_cast<char*>(name), 0, nullptr);
+}
+
+// This is called from NS_LogInit() and from the stack walking functions, but
+// only the first call has any effect.  We need to call this function from both
+// places because it must run before any mutexes are created, and also before
+// any objects whose refcounts we're logging are created.  Running this
+// function during NS_LogInit() ensures that we meet the first criterion, and
+// running this function during the stack walking functions ensures we meet the
+// second criterion.
+MFBT_API void
+StackWalkInitCriticalAddress()
+{
+  if (gCriticalAddress.mInit) {
+    return;
+  }
+  gCriticalAddress.mInit = true;
+  // We must not do work when 'new_sem_from_pool' calls realloc, since
+  // it holds a non-reentrant spin-lock and we will quickly deadlock.
+  // new_sem_from_pool is not directly accessible using dlsym, so
+  // we force a situation where new_sem_from_pool is on the stack and
+  // use dladdr to check the addresses.
+
+  // malloc_logger can be set by external tools like 'Instruments' or 'leaks'
+  malloc_logger_t* old_malloc_logger = malloc_logger;
+  malloc_logger = my_malloc_logger;
+
+  pthread_cond_t cond;
+  int r = pthread_cond_init(&cond, 0);
+  MOZ_ASSERT(r == 0);
+  pthread_mutex_t mutex;
+  r = pthread_mutex_init(&mutex, 0);
+  MOZ_ASSERT(r == 0);
+  r = pthread_mutex_lock(&mutex);
+  MOZ_ASSERT(r == 0);
+  struct timespec abstime = { 0, 1 };
+  r = pthread_cond_timedwait_relative_np(&cond, &mutex, &abstime);
+
+  // restore the previous malloc logger
+  malloc_logger = old_malloc_logger;
+
+  MOZ_ASSERT(r == ETIMEDOUT);
+  r = pthread_mutex_unlock(&mutex);
+  MOZ_ASSERT(r == 0);
+  r = pthread_mutex_destroy(&mutex);
+  MOZ_ASSERT(r == 0);
+  r = pthread_cond_destroy(&cond);
+  MOZ_ASSERT(r == 0);
+}
+
+static bool
+IsCriticalAddress(void* aPC)
+{
+  return gCriticalAddress.mAddr == aPC;
+}
+#else
+static bool
+IsCriticalAddress(void* aPC)
+{
+  return false;
+}
+// We still initialize gCriticalAddress.mInit so that this code behaves
+// the same on all platforms. Otherwise a failure to init would be visible
+// only on OS X.
+MFBT_API void
+StackWalkInitCriticalAddress()
+{
+  gCriticalAddress.mInit = true;
+}
+#endif
+
+#if defined(_WIN32) && (defined(_M_IX86) || defined(_M_AMD64) || defined(_M_IA64)) // WIN32 x86 stack walking code
+
+#include <windows.h>
+#include <process.h>
+#include <stdio.h>
+#include <malloc.h>
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/StackWalk_windows.h"
+
+#include <imagehlp.h>
+// We need a way to know if we are building for WXP (or later), as if we are, we
+// need to use the newer 64-bit APIs. API_VERSION_NUMBER seems to fit the bill.
+// A value of 9 indicates we want to use the new APIs.
+#if API_VERSION_NUMBER < 9
+#error Too old imagehlp.h
+#endif
+
+struct WalkStackData
+{
+  // Are we walking the stack of the calling thread? Note that we need to avoid
+  // calling fprintf and friends if this is false, in order to avoid deadlocks.
+  bool walkCallingThread;
+  uint32_t skipFrames;
+  HANDLE thread;
+  HANDLE process;
+  HANDLE eventStart;
+  HANDLE eventEnd;
+  void** pcs;
+  uint32_t pc_size;
+  uint32_t pc_count;
+  uint32_t pc_max;
+  void** sps;
+  uint32_t sp_size;
+  uint32_t sp_count;
+  void* platformData;
+};
+
+DWORD gStackWalkThread;
+CRITICAL_SECTION gDbgHelpCS;
+
+// Routine to print an error message to standard error.
+static void
+PrintError(const char* aPrefix)
+{
+  LPSTR lpMsgBuf;
+  DWORD lastErr = GetLastError();
+  FormatMessageA(
+    FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+    nullptr,
+    lastErr,
+    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+    (LPSTR)&lpMsgBuf,
+    0,
+    nullptr
+  );
+  fprintf(stderr, "### ERROR: %s: %s",
+          aPrefix, lpMsgBuf ? lpMsgBuf : "(null)\n");
+  fflush(stderr);
+  LocalFree(lpMsgBuf);
+}
+
+static unsigned int WINAPI WalkStackThread(void* aData);
+
+static bool
+EnsureWalkThreadReady()
+{
+  static bool walkThreadReady = false;
+  static HANDLE stackWalkThread = nullptr;
+  static HANDLE readyEvent = nullptr;
+
+  if (walkThreadReady) {
+    return walkThreadReady;
+  }
+
+  if (!stackWalkThread) {
+    readyEvent = ::CreateEvent(nullptr, FALSE /* auto-reset*/,
+                               FALSE /* initially non-signaled */,
+                               nullptr);
+    if (!readyEvent) {
+      PrintError("CreateEvent");
+      return false;
+    }
+
+    unsigned int threadID;
+    stackWalkThread = (HANDLE)_beginthreadex(nullptr, 0, WalkStackThread,
+                                             (void*)readyEvent, 0, &threadID);
+    if (!stackWalkThread) {
+      PrintError("CreateThread");
+      ::CloseHandle(readyEvent);
+      readyEvent = nullptr;
+      return false;
+    }
+    gStackWalkThread = threadID;
+    ::CloseHandle(stackWalkThread);
+  }
+
+  MOZ_ASSERT((stackWalkThread && readyEvent) ||
+             (!stackWalkThread && !readyEvent));
+
+  // The thread was created. Try to wait an arbitrary amount of time (1 second
+  // should be enough) for its event loop to start before posting events to it.
+  DWORD waitRet = ::WaitForSingleObject(readyEvent, 1000);
+  if (waitRet == WAIT_TIMEOUT) {
+    // We get a timeout if we're called during static initialization because
+    // the thread will only start executing after we return so it couldn't
+    // have signalled the event. If that is the case, give up for now and
+    // try again next time we're called.
+    return false;
+  }
+  ::CloseHandle(readyEvent);
+  stackWalkThread = nullptr;
+  readyEvent = nullptr;
+
+
+  ::InitializeCriticalSection(&gDbgHelpCS);
+
+  return walkThreadReady = true;
+}
+
+static void
+WalkStackMain64(struct WalkStackData* aData)
+{
+  // Get a context for the specified thread.
+  CONTEXT context;
+  if (!aData->platformData) {
+    memset(&context, 0, sizeof(CONTEXT));
+    context.ContextFlags = CONTEXT_FULL;
+    if (!GetThreadContext(aData->thread, &context)) {
+      if (aData->walkCallingThread) {
+        PrintError("GetThreadContext");
+      }
+      return;
+    }
+  } else {
+    context = *static_cast<CONTEXT*>(aData->platformData);
+  }
+
+#if defined(_M_IX86) || defined(_M_IA64)
+  // Setup initial stack frame to walk from.
+  STACKFRAME64 frame64;
+  memset(&frame64, 0, sizeof(frame64));
+#ifdef _M_IX86
+  frame64.AddrPC.Offset    = context.Eip;
+  frame64.AddrStack.Offset = context.Esp;
+  frame64.AddrFrame.Offset = context.Ebp;
+#elif defined _M_IA64
+  frame64.AddrPC.Offset    = context.StIIP;
+  frame64.AddrStack.Offset = context.SP;
+  frame64.AddrFrame.Offset = context.RsBSP;
+#endif
+  frame64.AddrPC.Mode      = AddrModeFlat;
+  frame64.AddrStack.Mode   = AddrModeFlat;
+  frame64.AddrFrame.Mode   = AddrModeFlat;
+  frame64.AddrReturn.Mode  = AddrModeFlat;
+#endif
+
+  // Skip our own stack walking frames.
+  int skip = (aData->walkCallingThread ? 3 : 0) + aData->skipFrames;
+
+  // Now walk the stack.
+  while (true) {
+    DWORD64 addr;
+    DWORD64 spaddr;
+
+#if defined(_M_IX86) || defined(_M_IA64)
+    // 32-bit frame unwinding.
+    // Debug routines are not threadsafe, so grab the lock.
+    EnterCriticalSection(&gDbgHelpCS);
+    BOOL ok = StackWalk64(
+#if defined _M_IA64
+      IMAGE_FILE_MACHINE_IA64,
+#elif defined _M_IX86
+      IMAGE_FILE_MACHINE_I386,
+#endif
+      aData->process,
+      aData->thread,
+      &frame64,
+      &context,
+      nullptr,
+      SymFunctionTableAccess64, // function table access routine
+      SymGetModuleBase64,       // module base routine
+      0
+    );
+    LeaveCriticalSection(&gDbgHelpCS);
+
+    if (ok) {
+      addr = frame64.AddrPC.Offset;
+      spaddr = frame64.AddrStack.Offset;
+    } else {
+      addr = 0;
+      spaddr = 0;
+      if (aData->walkCallingThread) {
+        PrintError("WalkStack64");
+      }
+    }
+
+    if (!ok) {
+      break;
+    }
+
+#elif defined(_M_AMD64)
+    // 64-bit frame unwinding.
+    // Try to look up unwind metadata for the current function.
+    ULONG64 imageBase;
+    PRUNTIME_FUNCTION runtimeFunction =
+      RtlLookupFunctionEntry(context.Rip, &imageBase, NULL);
+
+    if (!runtimeFunction) {
+      // Alas, this is probably a JIT frame, for which we don't generate unwind
+      // info and so we have to give up.
+      break;
+    }
+
+    PVOID dummyHandlerData;
+    ULONG64 dummyEstablisherFrame;
+    RtlVirtualUnwind(UNW_FLAG_NHANDLER,
+                     imageBase,
+                     context.Rip,
+                     runtimeFunction,
+                     &context,
+                     &dummyHandlerData,
+                     &dummyEstablisherFrame,
+                     nullptr);
+
+    addr = context.Rip;
+    spaddr = context.Rsp;
+
+#else
+#error "unknown platform"
+#endif
+
+    if (addr == 0) {
+      break;
+    }
+
+    if (skip-- > 0) {
+      continue;
+    }
+
+    if (aData->pc_count < aData->pc_size) {
+      aData->pcs[aData->pc_count] = (void*)addr;
+    }
+    ++aData->pc_count;
+
+    if (aData->sp_count < aData->sp_size) {
+      aData->sps[aData->sp_count] = (void*)spaddr;
+    }
+    ++aData->sp_count;
+
+    if (aData->pc_max != 0 && aData->pc_count == aData->pc_max) {
+      break;
+    }
+
+#if defined(_M_IX86) || defined(_M_IA64)
+    if (frame64.AddrReturn.Offset == 0) {
+      break;
+    }
+#endif
+  }
+}
+
+// The JIT needs to allocate executable memory. Because of the inanity of
+// the win64 APIs, this requires locks that stalk walkers also need. Provide
+// another lock to allow synchronization around these resources.
+#ifdef _M_AMD64
+
+struct CriticalSectionAutoInitializer {
+    CRITICAL_SECTION lock;
+
+    CriticalSectionAutoInitializer() {
+      InitializeCriticalSection(&lock);
+    }
+};
+
+static CriticalSectionAutoInitializer gWorkaroundLock;
+
+#endif // _M_AMD64
+
+MFBT_API void
+AcquireStackWalkWorkaroundLock()
+{
+#ifdef _M_AMD64
+  EnterCriticalSection(&gWorkaroundLock.lock);
+#endif
+}
+
+MFBT_API bool
+TryAcquireStackWalkWorkaroundLock()
+{
+#ifdef _M_AMD64
+  return TryEnterCriticalSection(&gWorkaroundLock.lock);
+#else
+  return true;
+#endif
+}
+
+MFBT_API void
+ReleaseStackWalkWorkaroundLock()
+{
+#ifdef _M_AMD64
+  LeaveCriticalSection(&gWorkaroundLock.lock);
+#endif
+}
+
+static unsigned int WINAPI
+WalkStackThread(void* aData)
+{
+  BOOL msgRet;
+  MSG msg;
+
+  // Call PeekMessage to force creation of a message queue so that
+  // other threads can safely post events to us.
+  ::PeekMessage(&msg, nullptr, WM_USER, WM_USER, PM_NOREMOVE);
+
+  // and tell the thread that created us that we're ready.
+  HANDLE readyEvent = (HANDLE)aData;
+  ::SetEvent(readyEvent);
+
+  while ((msgRet = ::GetMessage(&msg, (HWND)-1, 0, 0)) != 0) {
+    if (msgRet == -1) {
+      PrintError("GetMessage");
+    } else {
+      DWORD ret;
+
+      struct WalkStackData* data = (WalkStackData*)msg.lParam;
+      if (!data) {
+        continue;
+      }
+
+      // Don't suspend the calling thread until it's waiting for
+      // us; otherwise the number of frames on the stack could vary.
+      ret = ::WaitForSingleObject(data->eventStart, INFINITE);
+      if (ret != WAIT_OBJECT_0) {
+        PrintError("WaitForSingleObject");
+      }
+
+      // Suspend the calling thread, dump his stack, and then resume him.
+      // He's currently waiting for us to finish so now should be a good time.
+      ret = ::SuspendThread(data->thread);
+      if (ret == -1) {
+        PrintError("ThreadSuspend");
+      } else {
+        WalkStackMain64(data);
+
+        ret = ::ResumeThread(data->thread);
+        if (ret == -1) {
+          PrintError("ThreadResume");
+        }
+      }
+
+      ::SetEvent(data->eventEnd);
+    }
+  }
+
+  return 0;
+}
+
+/**
+ * Walk the stack, translating PC's found into strings and recording the
+ * chain in aBuffer. For this to work properly, the DLLs must be rebased
+ * so that the address in the file agrees with the address in memory.
+ * Otherwise StackWalk will return FALSE when it hits a frame in a DLL
+ * whose in memory address doesn't match its in-file address.
+ */
+
+MFBT_API bool
+MozStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+             uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
+             void* aPlatformData)
+{
+  StackWalkInitCriticalAddress();
+  static HANDLE myProcess = nullptr;
+  HANDLE myThread;
+  DWORD walkerReturn;
+  struct WalkStackData data;
+
+  if (!EnsureWalkThreadReady()) {
+    return false;
+  }
+
+  HANDLE currentThread = ::GetCurrentThread();
+  HANDLE targetThread =
+    aThread ? reinterpret_cast<HANDLE>(aThread) : currentThread;
+  data.walkCallingThread = (targetThread == currentThread);
+
+  // Have to duplicate handle to get a real handle.
+  if (!myProcess) {
+    if (!::DuplicateHandle(::GetCurrentProcess(),
+                           ::GetCurrentProcess(),
+                           ::GetCurrentProcess(),
+                           &myProcess,
+                           PROCESS_ALL_ACCESS, FALSE, 0)) {
+      if (data.walkCallingThread) {
+        PrintError("DuplicateHandle (process)");
+      }
+      return false;
+    }
+  }
+  if (!::DuplicateHandle(::GetCurrentProcess(),
+                         targetThread,
+                         ::GetCurrentProcess(),
+                         &myThread,
+                         THREAD_ALL_ACCESS, FALSE, 0)) {
+    if (data.walkCallingThread) {
+      PrintError("DuplicateHandle (thread)");
+    }
+    return false;
+  }
+
+  data.skipFrames = aSkipFrames;
+  data.thread = myThread;
+  data.process = myProcess;
+  void* local_pcs[1024];
+  data.pcs = local_pcs;
+  data.pc_count = 0;
+  data.pc_size = ArrayLength(local_pcs);
+  data.pc_max = aMaxFrames;
+  void* local_sps[1024];
+  data.sps = local_sps;
+  data.sp_count = 0;
+  data.sp_size = ArrayLength(local_sps);
+  data.platformData = aPlatformData;
+
+  if (aThread) {
+    // If we're walking the stack of another thread, we don't need to
+    // use a separate walker thread.
+    WalkStackMain64(&data);
+
+    if (data.pc_count > data.pc_size) {
+      data.pcs = (void**)_alloca(data.pc_count * sizeof(void*));
+      data.pc_size = data.pc_count;
+      data.pc_count = 0;
+      data.sps = (void**)_alloca(data.sp_count * sizeof(void*));
+      data.sp_size = data.sp_count;
+      data.sp_count = 0;
+      WalkStackMain64(&data);
+    }
+  } else {
+    data.eventStart = ::CreateEvent(nullptr, FALSE /* auto-reset*/,
+                                    FALSE /* initially non-signaled */, nullptr);
+    data.eventEnd = ::CreateEvent(nullptr, FALSE /* auto-reset*/,
+                                  FALSE /* initially non-signaled */, nullptr);
+
+    ::PostThreadMessage(gStackWalkThread, WM_USER, 0, (LPARAM)&data);
+
+    walkerReturn = ::SignalObjectAndWait(data.eventStart,
+                                         data.eventEnd, INFINITE, FALSE);
+    if (walkerReturn != WAIT_OBJECT_0 && data.walkCallingThread) {
+      PrintError("SignalObjectAndWait (1)");
+    }
+    if (data.pc_count > data.pc_size) {
+      data.pcs = (void**)_alloca(data.pc_count * sizeof(void*));
+      data.pc_size = data.pc_count;
+      data.pc_count = 0;
+      data.sps = (void**)_alloca(data.sp_count * sizeof(void*));
+      data.sp_size = data.sp_count;
+      data.sp_count = 0;
+      ::PostThreadMessage(gStackWalkThread, WM_USER, 0, (LPARAM)&data);
+      walkerReturn = ::SignalObjectAndWait(data.eventStart,
+                                           data.eventEnd, INFINITE, FALSE);
+      if (walkerReturn != WAIT_OBJECT_0 && data.walkCallingThread) {
+        PrintError("SignalObjectAndWait (2)");
+      }
+    }
+
+    ::CloseHandle(data.eventStart);
+    ::CloseHandle(data.eventEnd);
+  }
+
+  ::CloseHandle(myThread);
+
+  for (uint32_t i = 0; i < data.pc_count; ++i) {
+    (*aCallback)(i + 1, data.pcs[i], data.sps[i], aClosure);
+  }
+
+  return data.pc_count != 0;
+}
+
+
+static BOOL CALLBACK
+callbackEspecial64(
+  PCSTR aModuleName,
+  DWORD64 aModuleBase,
+  ULONG aModuleSize,
+  PVOID aUserContext)
+{
+  BOOL retval = TRUE;
+  DWORD64 addr = *(DWORD64*)aUserContext;
+
+  /*
+   * You'll want to control this if we are running on an
+   *  architecture where the addresses go the other direction.
+   * Not sure this is even a realistic consideration.
+   */
+  const BOOL addressIncreases = TRUE;
+
+  /*
+   * If it falls in side the known range, load the symbols.
+   */
+  if (addressIncreases
+      ? (addr >= aModuleBase && addr <= (aModuleBase + aModuleSize))
+      : (addr <= aModuleBase && addr >= (aModuleBase - aModuleSize))
+     ) {
+    retval = !!SymLoadModule64(GetCurrentProcess(), nullptr,
+                               (PSTR)aModuleName, nullptr,
+                               aModuleBase, aModuleSize);
+    if (!retval) {
+      PrintError("SymLoadModule64");
+    }
+  }
+
+  return retval;
+}
+
+/*
+ * SymGetModuleInfoEspecial
+ *
+ * Attempt to determine the module information.
+ * Bug 112196 says this DLL may not have been loaded at the time
+ *  SymInitialize was called, and thus the module information
+ *  and symbol information is not available.
+ * This code rectifies that problem.
+ */
+
+// New members were added to IMAGEHLP_MODULE64 (that show up in the
+// Platform SDK that ships with VC8, but not the Platform SDK that ships
+// with VC7.1, i.e., between DbgHelp 6.0 and 6.1), but we don't need to
+// use them, and it's useful to be able to function correctly with the
+// older library.  (Stock Windows XP SP2 seems to ship with dbghelp.dll
+// version 5.1.)  Since Platform SDK version need not correspond to
+// compiler version, and the version number in debughlp.h was NOT bumped
+// when these changes were made, ifdef based on a constant that was
+// added between these versions.
+#ifdef SSRVOPT_SETCONTEXT
+#define NS_IMAGEHLP_MODULE64_SIZE (((offsetof(IMAGEHLP_MODULE64, LoadedPdbName) + sizeof(DWORD64) - 1) / sizeof(DWORD64)) * sizeof(DWORD64))
+#else
+#define NS_IMAGEHLP_MODULE64_SIZE sizeof(IMAGEHLP_MODULE64)
+#endif
+
+BOOL SymGetModuleInfoEspecial64(HANDLE aProcess, DWORD64 aAddr,
+                                PIMAGEHLP_MODULE64 aModuleInfo,
+                                PIMAGEHLP_LINE64 aLineInfo)
+{
+  BOOL retval = FALSE;
+
+  /*
+   * Init the vars if we have em.
+   */
+  aModuleInfo->SizeOfStruct = NS_IMAGEHLP_MODULE64_SIZE;
+  if (aLineInfo) {
+    aLineInfo->SizeOfStruct = sizeof(IMAGEHLP_LINE64);
+  }
+
+  /*
+   * Give it a go.
+   * It may already be loaded.
+   */
+  retval = SymGetModuleInfo64(aProcess, aAddr, aModuleInfo);
+  if (retval == FALSE) {
+    /*
+     * Not loaded, here's the magic.
+     * Go through all the modules.
+     */
+    // Need to cast to PENUMLOADED_MODULES_CALLBACK64 because the
+    // constness of the first parameter of
+    // PENUMLOADED_MODULES_CALLBACK64 varies over SDK versions (from
+    // non-const to const over time).  See bug 391848 and bug
+    // 415426.
+    BOOL enumRes = EnumerateLoadedModules64(
+      aProcess,
+      (PENUMLOADED_MODULES_CALLBACK64)callbackEspecial64,
+      (PVOID)&aAddr);
+    if (enumRes != FALSE) {
+      /*
+       * One final go.
+       * If it fails, then well, we have other problems.
+       */
+      retval = SymGetModuleInfo64(aProcess, aAddr, aModuleInfo);
+    }
+  }
+
+  /*
+   * If we got module info, we may attempt line info as well.
+   * We will not report failure if this does not work.
+   */
+  if (retval != FALSE && aLineInfo) {
+    DWORD displacement = 0;
+    BOOL lineRes = FALSE;
+    lineRes = SymGetLineFromAddr64(aProcess, aAddr, &displacement, aLineInfo);
+    if (!lineRes) {
+      // Clear out aLineInfo to indicate that it's not valid
+      memset(aLineInfo, 0, sizeof(*aLineInfo));
+    }
+  }
+
+  return retval;
+}
+
+static bool
+EnsureSymInitialized()
+{
+  static bool gInitialized = false;
+  bool retStat;
+
+  if (gInitialized) {
+    return gInitialized;
+  }
+
+  if (!EnsureWalkThreadReady()) {
+    return false;
+  }
+
+  SymSetOptions(SYMOPT_LOAD_LINES | SYMOPT_UNDNAME);
+  retStat = SymInitialize(GetCurrentProcess(), nullptr, TRUE);
+  if (!retStat) {
+    PrintError("SymInitialize");
+  }
+
+  gInitialized = retStat;
+  /* XXX At some point we need to arrange to call SymCleanup */
+
+  return retStat;
+}
+
+
+MFBT_API bool
+MozDescribeCodeAddress(void* aPC, MozCodeAddressDetails* aDetails)
+{
+  aDetails->library[0] = '\0';
+  aDetails->loffset = 0;
+  aDetails->filename[0] = '\0';
+  aDetails->lineno = 0;
+  aDetails->function[0] = '\0';
+  aDetails->foffset = 0;
+
+  if (!EnsureSymInitialized()) {
+    return false;
+  }
+
+  HANDLE myProcess = ::GetCurrentProcess();
+  BOOL ok;
+
+  // debug routines are not threadsafe, so grab the lock.
+  EnterCriticalSection(&gDbgHelpCS);
+
+  //
+  // Attempt to load module info before we attempt to resolve the symbol.
+  // This just makes sure we get good info if available.
+  //
+
+  DWORD64 addr = (DWORD64)aPC;
+  IMAGEHLP_MODULE64 modInfo;
+  IMAGEHLP_LINE64 lineInfo;
+  BOOL modInfoRes;
+  modInfoRes = SymGetModuleInfoEspecial64(myProcess, addr, &modInfo, &lineInfo);
+
+  if (modInfoRes) {
+    strncpy(aDetails->library, modInfo.LoadedImageName,
+                sizeof(aDetails->library));
+    aDetails->library[mozilla::ArrayLength(aDetails->library) - 1] = '\0';
+    aDetails->loffset = (char*)aPC - (char*)modInfo.BaseOfImage;
+
+    if (lineInfo.FileName) {
+      strncpy(aDetails->filename, lineInfo.FileName,
+                  sizeof(aDetails->filename));
+      aDetails->filename[mozilla::ArrayLength(aDetails->filename) - 1] = '\0';
+      aDetails->lineno = lineInfo.LineNumber;
+    }
+  }
+
+  ULONG64 buffer[(sizeof(SYMBOL_INFO) +
+    MAX_SYM_NAME * sizeof(TCHAR) + sizeof(ULONG64) - 1) / sizeof(ULONG64)];
+  PSYMBOL_INFO pSymbol = (PSYMBOL_INFO)buffer;
+  pSymbol->SizeOfStruct = sizeof(SYMBOL_INFO);
+  pSymbol->MaxNameLen = MAX_SYM_NAME;
+
+  DWORD64 displacement;
+  ok = SymFromAddr(myProcess, addr, &displacement, pSymbol);
+
+  if (ok) {
+    strncpy(aDetails->function, pSymbol->Name,
+                sizeof(aDetails->function));
+    aDetails->function[mozilla::ArrayLength(aDetails->function) - 1] = '\0';
+    aDetails->foffset = static_cast<ptrdiff_t>(displacement);
+  }
+
+  LeaveCriticalSection(&gDbgHelpCS); // release our lock
+  return true;
+}
+
+// i386 or PPC Linux stackwalking code
+#elif HAVE_DLADDR && (HAVE__UNWIND_BACKTRACE || MOZ_STACKWALK_SUPPORTS_LINUX || MOZ_STACKWALK_SUPPORTS_MACOSX)
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+// On glibc 2.1, the Dl_info api defined in <dlfcn.h> is only exposed
+// if __USE_GNU is defined.  I suppose its some kind of standards
+// adherence thing.
+//
+#if (__GLIBC_MINOR__ >= 1) && !defined(__USE_GNU)
+#define __USE_GNU
+#endif
+
+// This thing is exported by libstdc++
+// Yes, this is a gcc only hack
+#if defined(MOZ_DEMANGLE_SYMBOLS)
+#include <cxxabi.h>
+#endif // MOZ_DEMANGLE_SYMBOLS
+
+void DemangleSymbol(const char* aSymbol,
+                    char* aBuffer,
+                    int aBufLen)
+{
+  aBuffer[0] = '\0';
+
+#if defined(MOZ_DEMANGLE_SYMBOLS)
+  /* See demangle.h in the gcc source for the voodoo */
+  char* demangled = abi::__cxa_demangle(aSymbol, 0, 0, 0);
+
+  if (demangled) {
+    strncpy(aBuffer, demangled, aBufLen);
+    aBuffer[aBufLen - 1] = '\0';
+    free(demangled);
+  }
+#endif // MOZ_DEMANGLE_SYMBOLS
+}
+
+// {x86, ppc} x {Linux, Mac} stackwalking code.
+#if ((defined(__i386) || defined(PPC) || defined(__ppc__)) && \
+     (MOZ_STACKWALK_SUPPORTS_MACOSX || MOZ_STACKWALK_SUPPORTS_LINUX))
+
+MFBT_API bool
+MozStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+             uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
+             void* aPlatformData)
+{
+  MOZ_ASSERT(!aThread);
+  MOZ_ASSERT(!aPlatformData);
+  StackWalkInitCriticalAddress();
+
+  // Get the frame pointer
+  void** bp = (void**)__builtin_frame_address(0);
+
+  void* stackEnd;
+#if HAVE___LIBC_STACK_END
+  stackEnd = __libc_stack_end;
+#elif defined(XP_DARWIN)
+  stackEnd = pthread_get_stackaddr_np(pthread_self());
+#elif defined(ANDROID)
+  pthread_attr_t sattr;
+  pthread_attr_init(&sattr);
+  pthread_getattr_np(pthread_self(), &sattr);
+  void* stackBase = stackEnd = nullptr;
+  size_t stackSize = 0;
+  if (gettid() != getpid()) {
+    // bionic's pthread_attr_getstack doesn't tell the truth for the main
+    // thread (see bug 846670). So don't use it for the main thread.
+    if (!pthread_attr_getstack(&sattr, &stackBase, &stackSize)) {
+      stackEnd = static_cast<char*>(stackBase) + stackSize;
+    } else {
+      stackEnd = nullptr;
+    }
+  }
+  if (!stackEnd) {
+    // So consider the current frame pointer + an arbitrary size of 8MB
+    // (modulo overflow ; not really arbitrary as it's the default stack
+    // size for the main thread) if pthread_attr_getstack failed for
+    // some reason (or was skipped).
+    static const uintptr_t kMaxStackSize = 8 * 1024 * 1024;
+    uintptr_t maxStackStart = uintptr_t(-1) - kMaxStackSize;
+    uintptr_t stackStart = std::max(maxStackStart, uintptr_t(bp));
+    stackEnd = reinterpret_cast<void*>(stackStart + kMaxStackSize);
+  }
+#else
+#  error Unsupported configuration
+#endif
+  return FramePointerStackWalk(aCallback, aSkipFrames, aMaxFrames,
+                               aClosure, bp, stackEnd);
+}
+
+#elif defined(HAVE__UNWIND_BACKTRACE)
+
+// libgcc_s.so symbols _Unwind_Backtrace@@GCC_3.3 and _Unwind_GetIP@@GCC_3.0
+#include <unwind.h>
+
+struct unwind_info
+{
+  MozWalkStackCallback callback;
+  int skip;
+  int maxFrames;
+  int numFrames;
+  bool isCriticalAbort;
+  void* closure;
+};
+
+static _Unwind_Reason_Code
+unwind_callback(struct _Unwind_Context* context, void* closure)
+{
+  unwind_info* info = static_cast<unwind_info*>(closure);
+  void* pc = reinterpret_cast<void*>(_Unwind_GetIP(context));
+  // TODO Use something like '_Unwind_GetGR()' to get the stack pointer.
+  if (IsCriticalAddress(pc)) {
+    info->isCriticalAbort = true;
+    // We just want to stop the walk, so any error code will do.  Using
+    // _URC_NORMAL_STOP would probably be the most accurate, but it is not
+    // defined on Android for ARM.
+    return _URC_FOREIGN_EXCEPTION_CAUGHT;
+  }
+  if (--info->skip < 0) {
+    info->numFrames++;
+    (*info->callback)(info->numFrames, pc, nullptr, info->closure);
+    if (info->maxFrames != 0 && info->numFrames == info->maxFrames) {
+      // Again, any error code that stops the walk will do.
+      return _URC_FOREIGN_EXCEPTION_CAUGHT;
+    }
+  }
+  return _URC_NO_REASON;
+}
+
+MFBT_API bool
+MozStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+             uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
+             void* aPlatformData)
+{
+  MOZ_ASSERT(!aThread);
+  MOZ_ASSERT(!aPlatformData);
+  StackWalkInitCriticalAddress();
+  unwind_info info;
+  info.callback = aCallback;
+  info.skip = aSkipFrames + 1;
+  info.maxFrames = aMaxFrames;
+  info.numFrames = 0;
+  info.isCriticalAbort = false;
+  info.closure = aClosure;
+
+  (void)_Unwind_Backtrace(unwind_callback, &info);
+
+  // We ignore the return value from _Unwind_Backtrace and instead determine
+  // the outcome from |info|.  There are two main reasons for this:
+  // - On ARM/Android bionic's _Unwind_Backtrace usually (always?) returns
+  //   _URC_FAILURE.  See
+  //   https://bugzilla.mozilla.org/show_bug.cgi?id=717853#c110.
+  // - If aMaxFrames != 0, we want to stop early, and the only way to do that
+  //   is to make unwind_callback return something other than _URC_NO_REASON,
+  //   which causes _Unwind_Backtrace to return a non-success code.
+  if (info.isCriticalAbort) {
+    return false;
+  }
+  return info.numFrames != 0;
+}
+
+#endif
+
+bool MFBT_API
+MozDescribeCodeAddress(void* aPC, MozCodeAddressDetails* aDetails)
+{
+  aDetails->library[0] = '\0';
+  aDetails->loffset = 0;
+  aDetails->filename[0] = '\0';
+  aDetails->lineno = 0;
+  aDetails->function[0] = '\0';
+  aDetails->foffset = 0;
+
+  Dl_info info;
+  int ok = dladdr(aPC, &info);
+  if (!ok) {
+    return true;
+  }
+
+  strncpy(aDetails->library, info.dli_fname, sizeof(aDetails->library));
+  aDetails->library[mozilla::ArrayLength(aDetails->library) - 1] = '\0';
+  aDetails->loffset = (char*)aPC - (char*)info.dli_fbase;
+
+  const char* symbol = info.dli_sname;
+  if (!symbol || symbol[0] == '\0') {
+    return true;
+  }
+
+  DemangleSymbol(symbol, aDetails->function, sizeof(aDetails->function));
+
+  if (aDetails->function[0] == '\0') {
+    // Just use the mangled symbol if demangling failed.
+    strncpy(aDetails->function, symbol, sizeof(aDetails->function));
+    aDetails->function[mozilla::ArrayLength(aDetails->function) - 1] = '\0';
+  }
+
+  aDetails->foffset = (char*)aPC - (char*)info.dli_saddr;
+  return true;
+}
+
+#else // unsupported platform.
+
+MFBT_API bool
+MozStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+             uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
+             void* aPlatformData)
+{
+  MOZ_ASSERT(!aThread);
+  MOZ_ASSERT(!aPlatformData);
+  return false;
+}
+
+MFBT_API bool
+MozDescribeCodeAddress(void* aPC, MozCodeAddressDetails* aDetails)
+{
+  aDetails->library[0] = '\0';
+  aDetails->loffset = 0;
+  aDetails->filename[0] = '\0';
+  aDetails->lineno = 0;
+  aDetails->function[0] = '\0';
+  aDetails->foffset = 0;
+  return false;
+}
+
+#endif
+
+#if defined(XP_WIN) || defined (XP_MACOSX) || defined (XP_LINUX)
+namespace mozilla {
+bool
+FramePointerStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+                      uint32_t aMaxFrames, void* aClosure, void** bp,
+                      void* aStackEnd)
+{
+  // Stack walking code courtesy Kipp's "leaky".
+
+  int32_t skip = aSkipFrames;
+  uint32_t numFrames = 0;
+  while (bp) {
+    void** next = (void**)*bp;
+    // bp may not be a frame pointer on i386 if code was compiled with
+    // -fomit-frame-pointer, so do some sanity checks.
+    // (bp should be a frame pointer on ppc(64) but checking anyway may help
+    // a little if the stack has been corrupted.)
+    // We don't need to check against the begining of the stack because
+    // we can assume that bp > sp
+    if (next <= bp ||
+        next > aStackEnd ||
+        (uintptr_t(next) & 3)) {
+      break;
+    }
+#if (defined(__ppc__) && defined(XP_MACOSX)) || defined(__powerpc64__)
+    // ppc mac or powerpc64 linux
+    void* pc = *(bp + 2);
+    bp += 3;
+#else // i386 or powerpc32 linux
+    void* pc = *(bp + 1);
+    bp += 2;
+#endif
+    if (IsCriticalAddress(pc)) {
+      return false;
+    }
+    if (--skip < 0) {
+      // Assume that the SP points to the BP of the function
+      // it called. We can't know the exact location of the SP
+      // but this should be sufficient for our use the SP
+      // to order elements on the stack.
+      numFrames++;
+      (*aCallback)(numFrames, pc, bp, aClosure);
+      if (aMaxFrames != 0 && numFrames == aMaxFrames) {
+        break;
+      }
+    }
+    bp = next;
+  }
+  return numFrames != 0;
+}
+} // namespace mozilla
+
+#else
+
+namespace mozilla {
+MFBT_API bool
+FramePointerStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+                      void* aClosure, void** aBp)
+{
+  return false;
+}
+}
+
+#endif
+
+MFBT_API void
+MozFormatCodeAddressDetails(char* aBuffer, uint32_t aBufferSize,
+                            uint32_t aFrameNumber, void* aPC,
+                            const MozCodeAddressDetails* aDetails)
+{
+  MozFormatCodeAddress(aBuffer, aBufferSize,
+                       aFrameNumber, aPC, aDetails->function,
+                       aDetails->library, aDetails->loffset,
+                       aDetails->filename, aDetails->lineno);
+}
+
+MFBT_API void
+MozFormatCodeAddress(char* aBuffer, uint32_t aBufferSize, uint32_t aFrameNumber,
+                     const void* aPC, const char* aFunction,
+                     const char* aLibrary, ptrdiff_t aLOffset,
+                     const char* aFileName, uint32_t aLineNo)
+{
+  const char* function = aFunction && aFunction[0] ? aFunction : "???";
+  if (aFileName && aFileName[0]) {
+    // We have a filename and (presumably) a line number. Use them.
+    snprintf(aBuffer, aBufferSize,
+             "#%02u: %s (%s:%u)",
+             aFrameNumber, function, aFileName, aLineNo);
+  } else if (aLibrary && aLibrary[0]) {
+    // We have no filename, but we do have a library name. Use it and the
+    // library offset, and print them in a way that scripts like
+    // fix_{linux,macosx}_stacks.py can easily post-process.
+    snprintf(aBuffer, aBufferSize,
+             "#%02u: %s[%s +0x%" PRIxPTR "]",
+             aFrameNumber, function, aLibrary, static_cast<uintptr_t>(aLOffset));
+  } else {
+    // We have nothing useful to go on. (The format string is split because
+    // '??)' is a trigraph and causes a warning, sigh.)
+    snprintf(aBuffer, aBufferSize,
+             "#%02u: ??? (???:???" ")",
+             aFrameNumber);
+  }
+}
diff --git a/mozglue/misc/StackWalk.h b/mozglue/misc/StackWalk.h
new file mode 100644
index 000000000..534c0bd82
--- /dev/null
+++ b/mozglue/misc/StackWalk.h
@@ -0,0 +1,163 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* API for getting a stack trace of the C/C++ stack on the current thread */
+
+#ifndef mozilla_StackWalk_h
+#define mozilla_StackWalk_h
+
+/* WARNING: This file is intended to be included from C or C++ files. */
+
+#include "mozilla/Types.h"
+#include <stdint.h>
+
+/**
+ * The callback for MozStackWalk.
+ *
+ * @param aFrameNumber  The frame number (starts at 1, not 0).
+ * @param aPC           The program counter value.
+ * @param aSP           The best approximation possible of what the stack
+ *                      pointer will be pointing to when the execution returns
+ *                      to executing that at aPC. If no approximation can
+ *                      be made it will be nullptr.
+ * @param aClosure      Extra data passed in via MozStackWalk().
+ */
+typedef void
+(*MozWalkStackCallback)(uint32_t aFrameNumber, void* aPC, void* aSP,
+                        void* aClosure);
+
+/**
+ * Call aCallback for the C/C++ stack frames on the current thread, from
+ * the caller of MozStackWalk to main (or above).
+ *
+ * @param aCallback    Callback function, called once per frame.
+ * @param aSkipFrames  Number of initial frames to skip.  0 means that
+ *                     the first callback will be for the caller of
+ *                     MozStackWalk.
+ * @param aMaxFrames   Maximum number of frames to trace.  0 means no limit.
+ * @param aClosure     Caller-supplied data passed through to aCallback.
+ * @param aThread      The thread for which the stack is to be retrieved.
+ *                     Passing null causes us to walk the stack of the
+ *                     current thread. On Windows, this is a thread HANDLE.
+ *                     It is currently not supported on any other platform.
+ * @param aPlatformData Platform specific data that can help in walking the
+ *                      stack, this should be nullptr unless you really know
+ *                      what you're doing! This needs to be a pointer to a
+ *                      CONTEXT on Windows and should not be passed on other
+ *                      platforms.
+ *
+ * May skip some stack frames due to compiler optimizations or code
+ * generation.
+ *
+ */
+MFBT_API bool
+MozStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+             uint32_t aMaxFrames, void* aClosure, uintptr_t aThread,
+             void* aPlatformData);
+
+typedef struct
+{
+  /*
+   * The name of the shared library or executable containing an
+   * address and the address's offset within that library, or empty
+   * string and zero if unknown.
+   */
+  char library[256];
+  ptrdiff_t loffset;
+  /*
+   * The name of the file name and line number of the code
+   * corresponding to the address, or empty string and zero if
+   * unknown.
+   */
+  char filename[256];
+  unsigned long lineno;
+  /*
+   * The name of the function containing an address and the address's
+   * offset within that function, or empty string and zero if unknown.
+   */
+  char function[256];
+  ptrdiff_t foffset;
+} MozCodeAddressDetails;
+
+/**
+ * For a given pointer to code, fill in the pieces of information used
+ * when printing a stack trace.
+ *
+ * @param aPC         The code address.
+ * @param aDetails    A structure to be filled in with the result.
+ */
+MFBT_API bool
+MozDescribeCodeAddress(void* aPC, MozCodeAddressDetails* aDetails);
+
+/**
+ * Format the information about a code address in a format suitable for
+ * stack traces on the current platform.  When available, this string
+ * should contain the function name, source file, and line number.  When
+ * these are not available, library and offset should be reported, if
+ * possible.
+ *
+ * Note that this output is parsed by several scripts including the fix*.py and
+ * make-tree.pl scripts in tools/rb/. It should only be change with care, and
+ * in conjunction with those scripts.
+ *
+ * @param aBuffer      A string to be filled in with the description.
+ *                     The string will always be null-terminated.
+ * @param aBufferSize  The size, in bytes, of aBuffer, including
+ *                     room for the terminating null.  If the information
+ *                     to be printed would be larger than aBuffer, it
+ *                     will be truncated so that aBuffer[aBufferSize-1]
+ *                     is the terminating null.
+ * @param aFrameNumber The frame number.
+ * @param aPC          The code address.
+ * @param aFunction    The function name. Possibly null or the empty string.
+ * @param aLibrary     The library name. Possibly null or the empty string.
+ * @param aLOffset     The library offset.
+ * @param aFileName    The filename. Possibly null or the empty string.
+ * @param aLineNo      The line number. Possibly zero.
+ */
+MFBT_API void
+MozFormatCodeAddress(char* aBuffer, uint32_t aBufferSize, uint32_t aFrameNumber,
+                     const void* aPC, const char* aFunction,
+                     const char* aLibrary, ptrdiff_t aLOffset,
+                     const char* aFileName, uint32_t aLineNo);
+
+/**
+ * Format the information about a code address in the same fashion as
+ * MozFormatCodeAddress.
+ *
+ * @param aBuffer      A string to be filled in with the description.
+ *                     The string will always be null-terminated.
+ * @param aBufferSize  The size, in bytes, of aBuffer, including
+ *                     room for the terminating null.  If the information
+ *                     to be printed would be larger than aBuffer, it
+ *                     will be truncated so that aBuffer[aBufferSize-1]
+ *                     is the terminating null.
+ * @param aFrameNumber The frame number.
+ * @param aPC          The code address.
+ * @param aDetails     The value filled in by MozDescribeCodeAddress(aPC).
+ */
+MFBT_API void
+MozFormatCodeAddressDetails(char* aBuffer, uint32_t aBufferSize,
+                            uint32_t aFrameNumber, void* aPC,
+                            const MozCodeAddressDetails* aDetails);
+
+namespace mozilla {
+
+MFBT_API bool
+FramePointerStackWalk(MozWalkStackCallback aCallback, uint32_t aSkipFrames,
+                      uint32_t aMaxFrames, void* aClosure, void** aBp,
+                      void* aStackEnd);
+
+} // namespace mozilla
+
+/**
+ * Initialize the critical sections for this platform so that we can
+ * abort stack walks when needed.
+ */
+MFBT_API void
+StackWalkInitCriticalAddress(void);
+
+#endif
diff --git a/mozglue/misc/StackWalk_windows.h b/mozglue/misc/StackWalk_windows.h
new file mode 100644
index 000000000..5ffdd2068
--- /dev/null
+++ b/mozglue/misc/StackWalk_windows.h
@@ -0,0 +1,21 @@
+#ifndef mozilla_StackWalk_windows_h
+#define mozilla_StackWalk_windows_h
+
+#include "mozilla/Types.h"
+
+/**
+ * Allow stack walkers to work around the egregious win64 dynamic lookup table
+ * list API by locking around SuspendThread to avoid deadlock.
+ *
+ * See comment in StackWalk.cpp
+ */
+MFBT_API void
+AcquireStackWalkWorkaroundLock();
+
+MFBT_API bool
+TryAcquireStackWalkWorkaroundLock();
+
+MFBT_API void
+ReleaseStackWalkWorkaroundLock();
+
+#endif // mozilla_StackWalk_windows_h
diff --git a/mozglue/misc/TimeStamp.cpp b/mozglue/misc/TimeStamp.cpp
new file mode 100644
index 000000000..932b75c99
--- /dev/null
+++ b/mozglue/misc/TimeStamp.cpp
@@ -0,0 +1,92 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Implementation of the OS-independent methods of the TimeStamp class
+ */
+
+#include "mozilla/TimeStamp.h"
+#include <stdio.h>
+#include <string.h>
+
+namespace mozilla {
+
+/**
+ * Wrapper class used to initialize static data used by the TimeStamp class
+ */
+struct TimeStampInitialization
+{
+  /**
+   * First timestamp taken when the class static initializers are run. This
+   * timestamp is used to sanitize timestamps coming from different sources.
+   */
+  TimeStamp mFirstTimeStamp;
+
+  /**
+   * Timestamp representing the time when the process was created. This field
+   * is populated lazily the first time this information is required and is
+   * replaced every time the process is restarted.
+   */
+  TimeStamp mProcessCreation;
+
+  TimeStampInitialization()
+  {
+    TimeStamp::Startup();
+    mFirstTimeStamp = TimeStamp::Now();
+  };
+
+  ~TimeStampInitialization()
+  {
+    TimeStamp::Shutdown();
+  };
+};
+
+static TimeStampInitialization sInitOnce;
+
+MFBT_API TimeStamp
+TimeStamp::ProcessCreation(bool& aIsInconsistent)
+{
+  aIsInconsistent = false;
+
+  if (sInitOnce.mProcessCreation.IsNull()) {
+    char* mozAppRestart = getenv("MOZ_APP_RESTART");
+    TimeStamp ts;
+
+    /* When calling PR_SetEnv() with an empty value the existing variable may
+     * be unset or set to the empty string depending on the underlying platform
+     * thus we have to check if the variable is present and not empty. */
+    if (mozAppRestart && (strcmp(mozAppRestart, "") != 0)) {
+      /* Firefox was restarted, use the first time-stamp we've taken as the new
+       * process startup time. */
+      ts = sInitOnce.mFirstTimeStamp;
+    } else {
+      TimeStamp now = Now();
+      uint64_t uptime = ComputeProcessUptime();
+
+      ts = now - TimeDuration::FromMicroseconds(uptime);
+
+      if ((ts > sInitOnce.mFirstTimeStamp) || (uptime == 0)) {
+        /* If the process creation timestamp was inconsistent replace it with
+         * the first one instead and notify that a telemetry error was
+         * detected. */
+        aIsInconsistent = true;
+        ts = sInitOnce.mFirstTimeStamp;
+      }
+    }
+
+    sInitOnce.mProcessCreation = ts;
+  }
+
+  return sInitOnce.mProcessCreation;
+}
+
+void
+TimeStamp::RecordProcessRestart()
+{
+  sInitOnce.mProcessCreation = TimeStamp();
+}
+
+} // namespace mozilla
diff --git a/mozglue/misc/TimeStamp.h b/mozglue/misc/TimeStamp.h
new file mode 100644
index 000000000..a1a0eb360
--- /dev/null
+++ b/mozglue/misc/TimeStamp.h
@@ -0,0 +1,609 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_TimeStamp_h
+#define mozilla_TimeStamp_h
+
+#include <stdint.h>
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/TypeTraits.h"
+#include "mozilla/Types.h"
+
+namespace IPC {
+template<typename T> struct ParamTraits;
+} // namespace IPC
+
+#ifdef XP_WIN
+// defines TimeStampValue as a complex value keeping both
+// GetTickCount and QueryPerformanceCounter values
+#include "TimeStamp_windows.h"
+#endif
+
+namespace mozilla {
+
+#ifndef XP_WIN
+typedef uint64_t TimeStampValue;
+#endif
+
+class TimeStamp;
+
+/**
+ * Platform-specific implementation details of BaseTimeDuration.
+ */
+class BaseTimeDurationPlatformUtils
+{
+public:
+  static MFBT_API double ToSeconds(int64_t aTicks);
+  static MFBT_API double ToSecondsSigDigits(int64_t aTicks);
+  static MFBT_API int64_t TicksFromMilliseconds(double aMilliseconds);
+  static MFBT_API int64_t ResolutionInTicks();
+};
+
+/**
+ * Instances of this class represent the length of an interval of time.
+ * Negative durations are allowed, meaning the end is before the start.
+ *
+ * Internally the duration is stored as a int64_t in units of
+ * PR_TicksPerSecond() when building with NSPR interval timers, or a
+ * system-dependent unit when building with system clocks.  The
+ * system-dependent unit must be constant, otherwise the semantics of
+ * this class would be broken.
+ *
+ * The ValueCalculator template parameter determines how arithmetic
+ * operations are performed on the integer count of ticks (mValue).
+ */
+template <typename ValueCalculator>
+class BaseTimeDuration
+{
+public:
+  // The default duration is 0.
+  constexpr BaseTimeDuration() : mValue(0) {}
+  // Allow construction using '0' as the initial value, for readability,
+  // but no other numbers (so we don't have any implicit unit conversions).
+  struct _SomethingVeryRandomHere;
+  MOZ_IMPLICIT BaseTimeDuration(_SomethingVeryRandomHere* aZero) : mValue(0)
+  {
+    MOZ_ASSERT(!aZero, "Who's playing funny games here?");
+  }
+  // Default copy-constructor and assignment are OK
+
+  // Converting copy-constructor and assignment operator
+  template <typename E>
+  explicit BaseTimeDuration(const BaseTimeDuration<E>& aOther)
+    : mValue(aOther.mValue)
+  { }
+
+  template <typename E>
+  BaseTimeDuration& operator=(const BaseTimeDuration<E>& aOther)
+  {
+    mValue = aOther.mValue;
+    return *this;
+  }
+
+  double ToSeconds() const
+  {
+    if (mValue == INT64_MAX) {
+      return PositiveInfinity<double>();
+    }
+    if (mValue == INT64_MIN) {
+      return NegativeInfinity<double>();
+    }
+    return BaseTimeDurationPlatformUtils::ToSeconds(mValue);
+  }
+  // Return a duration value that includes digits of time we think to
+  // be significant.  This method should be used when displaying a
+  // time to humans.
+  double ToSecondsSigDigits() const
+  {
+    if (mValue == INT64_MAX) {
+      return PositiveInfinity<double>();
+    }
+    if (mValue == INT64_MIN) {
+      return NegativeInfinity<double>();
+    }
+    return BaseTimeDurationPlatformUtils::ToSecondsSigDigits(mValue);
+  }
+  double ToMilliseconds() const { return ToSeconds() * 1000.0; }
+  double ToMicroseconds() const { return ToMilliseconds() * 1000.0; }
+
+  // Using a double here is safe enough; with 53 bits we can represent
+  // durations up to over 280,000 years exactly.  If the units of
+  // mValue do not allow us to represent durations of that length,
+  // long durations are clamped to the max/min representable value
+  // instead of overflowing.
+  static inline BaseTimeDuration FromSeconds(double aSeconds)
+  {
+    return FromMilliseconds(aSeconds * 1000.0);
+  }
+  static BaseTimeDuration FromMilliseconds(double aMilliseconds)
+  {
+    if (aMilliseconds == PositiveInfinity<double>()) {
+      return Forever();
+    }
+    if (aMilliseconds == NegativeInfinity<double>()) {
+      return FromTicks(INT64_MIN);
+    }
+    return FromTicks(
+      BaseTimeDurationPlatformUtils::TicksFromMilliseconds(aMilliseconds));
+  }
+  static inline BaseTimeDuration FromMicroseconds(double aMicroseconds)
+  {
+    return FromMilliseconds(aMicroseconds / 1000.0);
+  }
+
+  static BaseTimeDuration Forever()
+  {
+    return FromTicks(INT64_MAX);
+  }
+
+  BaseTimeDuration operator+(const BaseTimeDuration& aOther) const
+  {
+    return FromTicks(ValueCalculator::Add(mValue, aOther.mValue));
+  }
+  BaseTimeDuration operator-(const BaseTimeDuration& aOther) const
+  {
+    return FromTicks(ValueCalculator::Subtract(mValue, aOther.mValue));
+  }
+  BaseTimeDuration& operator+=(const BaseTimeDuration& aOther)
+  {
+    mValue = ValueCalculator::Add(mValue, aOther.mValue);
+    return *this;
+  }
+  BaseTimeDuration& operator-=(const BaseTimeDuration& aOther)
+  {
+    mValue = ValueCalculator::Subtract(mValue, aOther.mValue);
+    return *this;
+  }
+  BaseTimeDuration operator-() const
+  {
+    // We don't just use FromTicks(ValueCalculator::Subtract(0, mValue))
+    // since that won't give the correct result for -TimeDuration::Forever().
+    int64_t ticks;
+    if (mValue == INT64_MAX) {
+      ticks = INT64_MIN;
+    } else if (mValue == INT64_MIN) {
+      ticks = INT64_MAX;
+    } else {
+      ticks = -mValue;
+    }
+
+    return FromTicks(ticks);
+  }
+
+private:
+  // Block double multiplier (slower, imprecise if long duration) - Bug 853398.
+  // If required, use MultDouble explicitly and with care.
+  BaseTimeDuration operator*(const double aMultiplier) const = delete;
+
+  // Block double divisor (for the same reason, and because dividing by
+  // fractional values would otherwise invoke the int64_t variant, and rounding
+  // the passed argument can then cause divide-by-zero) - Bug 1147491.
+  BaseTimeDuration operator/(const double aDivisor) const = delete;
+
+public:
+  BaseTimeDuration MultDouble(double aMultiplier) const
+  {
+    return FromTicks(ValueCalculator::Multiply(mValue, aMultiplier));
+  }
+  BaseTimeDuration operator*(const int32_t aMultiplier) const
+  {
+    return FromTicks(ValueCalculator::Multiply(mValue, aMultiplier));
+  }
+  BaseTimeDuration operator*(const uint32_t aMultiplier) const
+  {
+    return FromTicks(ValueCalculator::Multiply(mValue, aMultiplier));
+  }
+  BaseTimeDuration operator*(const int64_t aMultiplier) const
+  {
+    return FromTicks(ValueCalculator::Multiply(mValue, aMultiplier));
+  }
+  BaseTimeDuration operator*(const uint64_t aMultiplier) const
+  {
+    if (aMultiplier > INT64_MAX) {
+      return Forever();
+    }
+    return FromTicks(ValueCalculator::Multiply(mValue, aMultiplier));
+  }
+  BaseTimeDuration operator/(const int64_t aDivisor) const
+  {
+    MOZ_ASSERT(aDivisor != 0, "Division by zero");
+    return FromTicks(ValueCalculator::Divide(mValue, aDivisor));
+  }
+  double operator/(const BaseTimeDuration& aOther) const
+  {
+#ifndef MOZ_B2G
+    // Bug 1066388 - This fails on B2G ICS Emulator
+    MOZ_ASSERT(aOther.mValue != 0, "Division by zero");
+#endif
+    return ValueCalculator::DivideDouble(mValue, aOther.mValue);
+  }
+  BaseTimeDuration operator%(const BaseTimeDuration& aOther) const
+  {
+    MOZ_ASSERT(aOther.mValue != 0, "Division by zero");
+    return FromTicks(ValueCalculator::Modulo(mValue, aOther.mValue));
+  }
+
+  template<typename E>
+  bool operator<(const BaseTimeDuration<E>& aOther) const
+  {
+    return mValue < aOther.mValue;
+  }
+  template<typename E>
+  bool operator<=(const BaseTimeDuration<E>& aOther) const
+  {
+    return mValue <= aOther.mValue;
+  }
+  template<typename E>
+  bool operator>=(const BaseTimeDuration<E>& aOther) const
+  {
+    return mValue >= aOther.mValue;
+  }
+  template<typename E>
+  bool operator>(const BaseTimeDuration<E>& aOther) const
+  {
+    return mValue > aOther.mValue;
+  }
+  template<typename E>
+  bool operator==(const BaseTimeDuration<E>& aOther) const
+  {
+    return mValue == aOther.mValue;
+  }
+  template<typename E>
+  bool operator!=(const BaseTimeDuration<E>& aOther) const
+  {
+    return mValue != aOther.mValue;
+  }
+  bool IsZero() const
+  {
+    return mValue == 0;
+  }
+  explicit operator bool() const
+  {
+    return mValue != 0;
+  }
+
+  // Return a best guess at the system's current timing resolution,
+  // which might be variable.  BaseTimeDurations below this order of
+  // magnitude are meaningless, and those at the same order of
+  // magnitude or just above are suspect.
+  static BaseTimeDuration Resolution() {
+    return FromTicks(BaseTimeDurationPlatformUtils::ResolutionInTicks());
+  }
+
+  // We could define additional operators here:
+  // -- convert to/from other time units
+  // -- scale duration by a float
+  // but let's do that on demand.
+  // Comparing durations for equality will only lead to bugs on
+  // platforms with high-resolution timers.
+
+private:
+  friend class TimeStamp;
+  friend struct IPC::ParamTraits<mozilla::BaseTimeDuration<ValueCalculator>>;
+  template <typename>
+  friend class BaseTimeDuration;
+
+  static BaseTimeDuration FromTicks(int64_t aTicks)
+  {
+    BaseTimeDuration t;
+    t.mValue = aTicks;
+    return t;
+  }
+
+  static BaseTimeDuration FromTicks(double aTicks)
+  {
+    // NOTE: this MUST be a >= test, because int64_t(double(INT64_MAX))
+    // overflows and gives INT64_MIN.
+    if (aTicks >= double(INT64_MAX)) {
+      return FromTicks(INT64_MAX);
+    }
+
+    // This MUST be a <= test.
+    if (aTicks <= double(INT64_MIN)) {
+      return FromTicks(INT64_MIN);
+    }
+
+    return FromTicks(int64_t(aTicks));
+  }
+
+  // Duration, result is implementation-specific difference of two TimeStamps
+  int64_t mValue;
+};
+
+/**
+ * Perform arithmetic operations on the value of a BaseTimeDuration without
+ * doing strict checks on the range of values.
+ */
+class TimeDurationValueCalculator
+{
+public:
+  static int64_t Add(int64_t aA, int64_t aB) { return aA + aB; }
+  static int64_t Subtract(int64_t aA, int64_t aB) { return aA - aB; }
+
+  template <typename T>
+  static int64_t Multiply(int64_t aA, T aB)
+  {
+    static_assert(IsIntegral<T>::value,
+                  "Using integer multiplication routine with non-integer type."
+                  " Further specialization required");
+    return aA * static_cast<int64_t>(aB);
+  }
+
+  static int64_t Divide(int64_t aA, int64_t aB) { return aA / aB; }
+  static double DivideDouble(int64_t aA, int64_t aB)
+  {
+    return static_cast<double>(aA) / aB;
+  }
+  static int64_t Modulo(int64_t aA, int64_t aB) { return aA % aB; }
+};
+
+template <>
+inline int64_t
+TimeDurationValueCalculator::Multiply<double>(int64_t aA, double aB)
+{
+  return static_cast<int64_t>(aA * aB);
+}
+
+/**
+ * Specialization of BaseTimeDuration that uses TimeDurationValueCalculator for
+ * arithmetic on the mValue member.
+ *
+ * Use this class for time durations that are *not* expected to hold values of
+ * Forever (or the negative equivalent) or when such time duration are *not*
+ * expected to be used in arithmetic operations.
+ */
+typedef BaseTimeDuration<TimeDurationValueCalculator> TimeDuration;
+
+/**
+ * Instances of this class represent moments in time, or a special
+ * "null" moment. We do not use the non-monotonic system clock or
+ * local time, since they can be reset, causing apparent backward
+ * travel in time, which can confuse algorithms. Instead we measure
+ * elapsed time according to the system.  This time can never go
+ * backwards (i.e. it never wraps around, at least not in less than
+ * five million years of system elapsed time). It might not advance
+ * while the system is sleeping. If TimeStamp::SetNow() is not called
+ * at all for hours or days, we might not notice the passage of some
+ * of that time.
+ *
+ * We deliberately do not expose a way to convert TimeStamps to some
+ * particular unit. All you can do is compute a difference between two
+ * TimeStamps to get a TimeDuration. You can also add a TimeDuration
+ * to a TimeStamp to get a new TimeStamp. You can't do something
+ * meaningless like add two TimeStamps.
+ *
+ * Internally this is implemented as either a wrapper around
+ *   - high-resolution, monotonic, system clocks if they exist on this
+ *     platform
+ *   - PRIntervalTime otherwise.  We detect wraparounds of
+ *     PRIntervalTime and work around them.
+ *
+ * This class is similar to C++11's time_point, however it is
+ * explicitly nullable and provides an IsNull() method. time_point
+ * is initialized to the clock's epoch and provides a
+ * time_since_epoch() method that functions similiarly. i.e.
+ * t.IsNull() is equivalent to t.time_since_epoch() == decltype(t)::duration::zero();
+ */
+class TimeStamp
+{
+public:
+  /**
+   * Initialize to the "null" moment
+   */
+  constexpr TimeStamp() : mValue(0) {}
+  // Default copy-constructor and assignment are OK
+
+  /**
+   * The system timestamps are the same as the TimeStamp
+   * retrieved by mozilla::TimeStamp. Since we need this for
+   * vsync timestamps, we enable the creation of mozilla::TimeStamps
+   * on platforms that support vsync aligned refresh drivers / compositors
+   * Verified true as of Jan 31, 2015: B2G and OS X
+   * False on Windows 7
+   * UNTESTED ON OTHER PLATFORMS
+   */
+#if defined(MOZ_WIDGET_GONK) || defined(XP_DARWIN)
+  static TimeStamp FromSystemTime(int64_t aSystemTime)
+  {
+    static_assert(sizeof(aSystemTime) == sizeof(TimeStampValue),
+                  "System timestamp should be same units as TimeStampValue");
+    return TimeStamp(aSystemTime);
+  }
+#endif
+
+  /**
+   * Return true if this is the "null" moment
+   */
+  bool IsNull() const { return mValue == 0; }
+
+  /**
+   * Return true if this is not the "null" moment, may be used in tests, e.g.:
+   * |if (timestamp) { ... }|
+   */
+  explicit operator bool() const
+  {
+    return mValue != 0;
+  }
+
+  /**
+   * Return a timestamp reflecting the current elapsed system time. This
+   * is monotonically increasing (i.e., does not decrease) over the
+   * lifetime of this process' XPCOM session.
+   *
+   * Now() is trying to ensure the best possible precision on each platform,
+   * at least one millisecond.
+   *
+   * NowLoRes() has been introduced to workaround performance problems of
+   * QueryPerformanceCounter on the Windows platform.  NowLoRes() is giving
+   * lower precision, usually 15.6 ms, but with very good performance benefit.
+   * Use it for measurements of longer times, like >200ms timeouts.
+   */
+  static TimeStamp Now() { return Now(true); }
+  static TimeStamp NowLoRes() { return Now(false); }
+
+  /**
+   * Return a timestamp representing the time when the current process was
+   * created which will be comparable with other timestamps taken with this
+   * class. If the actual process creation time is detected to be inconsistent
+   * the @a aIsInconsistent parameter will be set to true, the returned
+   * timestamp however will still be valid though inaccurate.
+   *
+   * @param aIsInconsistent Set to true if an inconsistency was detected in the
+   * process creation time
+   * @returns A timestamp representing the time when the process was created,
+   * this timestamp is always valid even when errors are reported
+   */
+  static MFBT_API TimeStamp ProcessCreation(bool& aIsInconsistent);
+
+  /**
+   * Records a process restart. After this call ProcessCreation() will return
+   * the time when the browser was restarted instead of the actual time when
+   * the process was created.
+   */
+  static MFBT_API void RecordProcessRestart();
+
+  /**
+   * Compute the difference between two timestamps. Both must be non-null.
+   */
+  TimeDuration operator-(const TimeStamp& aOther) const
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    MOZ_ASSERT(!aOther.IsNull(), "Cannot compute with aOther null value");
+    static_assert(-INT64_MAX > INT64_MIN, "int64_t sanity check");
+    int64_t ticks = int64_t(mValue - aOther.mValue);
+    // Check for overflow.
+    if (mValue > aOther.mValue) {
+      if (ticks < 0) {
+        ticks = INT64_MAX;
+      }
+    } else {
+      if (ticks > 0) {
+        ticks = INT64_MIN;
+      }
+    }
+    return TimeDuration::FromTicks(ticks);
+  }
+
+  TimeStamp operator+(const TimeDuration& aOther) const
+  {
+    TimeStamp result = *this;
+    result += aOther;
+    return result;
+  }
+  TimeStamp operator-(const TimeDuration& aOther) const
+  {
+    TimeStamp result = *this;
+    result -= aOther;
+    return result;
+  }
+  TimeStamp& operator+=(const TimeDuration& aOther)
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    TimeStampValue value = mValue + aOther.mValue;
+    // Check for underflow.
+    // (We don't check for overflow because it's not obvious what the error
+    //  behavior should be in that case.)
+    if (aOther.mValue < 0 && value > mValue) {
+      value = 0;
+    }
+    mValue = value;
+    return *this;
+  }
+  TimeStamp& operator-=(const TimeDuration& aOther)
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    TimeStampValue value = mValue - aOther.mValue;
+    // Check for underflow.
+    // (We don't check for overflow because it's not obvious what the error
+    //  behavior should be in that case.)
+    if (aOther.mValue > 0 && value > mValue) {
+      value = 0;
+    }
+    mValue = value;
+    return *this;
+  }
+
+  bool operator<(const TimeStamp& aOther) const
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    MOZ_ASSERT(!aOther.IsNull(), "Cannot compute with aOther null value");
+    return mValue < aOther.mValue;
+  }
+  bool operator<=(const TimeStamp& aOther) const
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    MOZ_ASSERT(!aOther.IsNull(), "Cannot compute with aOther null value");
+    return mValue <= aOther.mValue;
+  }
+  bool operator>=(const TimeStamp& aOther) const
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    MOZ_ASSERT(!aOther.IsNull(), "Cannot compute with aOther null value");
+    return mValue >= aOther.mValue;
+  }
+  bool operator>(const TimeStamp& aOther) const
+  {
+    MOZ_ASSERT(!IsNull(), "Cannot compute with a null value");
+    MOZ_ASSERT(!aOther.IsNull(), "Cannot compute with aOther null value");
+    return mValue > aOther.mValue;
+  }
+  bool operator==(const TimeStamp& aOther) const
+  {
+    return IsNull()
+           ? aOther.IsNull()
+           : !aOther.IsNull() && mValue == aOther.mValue;
+  }
+  bool operator!=(const TimeStamp& aOther) const
+  {
+    return !(*this == aOther);
+  }
+
+  // Comparing TimeStamps for equality should be discouraged. Adding
+  // two TimeStamps, or scaling TimeStamps, is nonsense and must never
+  // be allowed.
+
+  static MFBT_API void Startup();
+  static MFBT_API void Shutdown();
+
+private:
+  friend struct IPC::ParamTraits<mozilla::TimeStamp>;
+  friend void StartupTimelineRecordExternal(int, uint64_t);
+
+  MOZ_IMPLICIT TimeStamp(TimeStampValue aValue) : mValue(aValue) {}
+
+  static MFBT_API TimeStamp Now(bool aHighResolution);
+
+  /**
+   * Computes the uptime of the current process in microseconds. The result
+   * is platform-dependent and needs to be checked against existing timestamps
+   * for consistency.
+   *
+   * @returns The number of microseconds since the calling process was started
+   *          or 0 if an error was encountered while computing the uptime
+   */
+  static MFBT_API uint64_t ComputeProcessUptime();
+
+  /**
+   * When built with PRIntervalTime, a value of 0 means this instance
+   * is "null". Otherwise, the low 32 bits represent a PRIntervalTime,
+   * and the high 32 bits represent a counter of the number of
+   * rollovers of PRIntervalTime that we've seen. This counter starts
+   * at 1 to avoid a real time colliding with the "null" value.
+   *
+   * PR_INTERVAL_MAX is set at 100,000 ticks per second. So the minimum
+   * time to wrap around is about 2^64/100000 seconds, i.e. about
+   * 5,849,424 years.
+   *
+   * When using a system clock, a value is system dependent.
+   */
+  TimeStampValue mValue;
+};
+
+} // namespace mozilla
+
+#endif /* mozilla_TimeStamp_h */
diff --git a/mozglue/misc/TimeStamp_darwin.cpp b/mozglue/misc/TimeStamp_darwin.cpp
new file mode 100644
index 000000000..f30bc9846
--- /dev/null
+++ b/mozglue/misc/TimeStamp_darwin.cpp
@@ -0,0 +1,206 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//
+// Implement TimeStamp::Now() with mach_absolute_time
+//
+// The "tick" unit for mach_absolute_time is defined using mach_timebase_info() which
+// gives a conversion ratio to nanoseconds. For more information see Apple's QA1398.
+//
+// This code is inspired by Chromium's time_mac.cc. The biggest
+// differences are that we explicitly initialize using
+// TimeStamp::Initialize() instead of lazily in Now() and that
+// we store the time value in ticks and convert when needed instead
+// of storing the time value in nanoseconds.
+
+#include <mach/mach_time.h>
+#include <sys/time.h>
+#include <sys/sysctl.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "mozilla/TimeStamp.h"
+
+// Estimate of the smallest duration of time we can measure.
+static uint64_t sResolution;
+static uint64_t sResolutionSigDigs;
+
+static const uint64_t kNsPerMs   =    1000000;
+static const uint64_t kUsPerSec  =    1000000;
+static const double kNsPerMsd    =    1000000.0;
+static const double kNsPerSecd   = 1000000000.0;
+
+static bool gInitialized = false;
+static double sNsPerTick;
+
+static uint64_t
+ClockTime()
+{
+  // mach_absolute_time is it when it comes to ticks on the Mac.  Other calls
+  // with less precision (such as TickCount) just call through to
+  // mach_absolute_time.
+  //
+  // At the time of writing mach_absolute_time returns the number of nanoseconds
+  // since boot. This won't overflow 64bits for 500+ years so we aren't going
+  // to worry about that possiblity
+  return mach_absolute_time();
+}
+
+static uint64_t
+ClockResolutionNs()
+{
+  uint64_t start = ClockTime();
+  uint64_t end = ClockTime();
+  uint64_t minres = (end - start);
+
+  // 10 total trials is arbitrary: what we're trying to avoid by
+  // looping is getting unlucky and being interrupted by a context
+  // switch or signal, or being bitten by paging/cache effects
+  for (int i = 0; i < 9; ++i) {
+    start = ClockTime();
+    end = ClockTime();
+
+    uint64_t candidate = (start - end);
+    if (candidate < minres) {
+      minres = candidate;
+    }
+  }
+
+  if (0 == minres) {
+    // measurable resolution is either incredibly low, ~1ns, or very
+    // high.  fall back on NSPR's resolution assumption
+    minres = 1 * kNsPerMs;
+  }
+
+  return minres;
+}
+
+namespace mozilla {
+
+double
+BaseTimeDurationPlatformUtils::ToSeconds(int64_t aTicks)
+{
+  MOZ_ASSERT(gInitialized, "calling TimeDuration too early");
+  return (aTicks * sNsPerTick) / kNsPerSecd;
+}
+
+double
+BaseTimeDurationPlatformUtils::ToSecondsSigDigits(int64_t aTicks)
+{
+  MOZ_ASSERT(gInitialized, "calling TimeDuration too early");
+  // don't report a value < mResolution ...
+  int64_t valueSigDigs = sResolution * (aTicks / sResolution);
+  // and chop off insignificant digits
+  valueSigDigs = sResolutionSigDigs * (valueSigDigs / sResolutionSigDigs);
+  return (valueSigDigs * sNsPerTick) / kNsPerSecd;
+}
+
+int64_t
+BaseTimeDurationPlatformUtils::TicksFromMilliseconds(double aMilliseconds)
+{
+  MOZ_ASSERT(gInitialized, "calling TimeDuration too early");
+  double result = (aMilliseconds * kNsPerMsd) / sNsPerTick;
+  if (result > INT64_MAX) {
+    return INT64_MAX;
+  } else if (result < INT64_MIN) {
+    return INT64_MIN;
+  }
+
+  return result;
+}
+
+int64_t
+BaseTimeDurationPlatformUtils::ResolutionInTicks()
+{
+  MOZ_ASSERT(gInitialized, "calling TimeDuration too early");
+  return static_cast<int64_t>(sResolution);
+}
+
+void
+TimeStamp::Startup()
+{
+  if (gInitialized) {
+    return;
+  }
+
+  mach_timebase_info_data_t timebaseInfo;
+  // Apple's QA1398 suggests that the output from mach_timebase_info
+  // will not change while a program is running, so it should be safe
+  // to cache the result.
+  kern_return_t kr = mach_timebase_info(&timebaseInfo);
+  if (kr != KERN_SUCCESS) {
+    MOZ_RELEASE_ASSERT(false, "mach_timebase_info failed");
+  }
+
+  sNsPerTick = double(timebaseInfo.numer) / timebaseInfo.denom;
+
+  sResolution = ClockResolutionNs();
+
+  // find the number of significant digits in sResolution, for the
+  // sake of ToSecondsSigDigits()
+  for (sResolutionSigDigs = 1;
+       !(sResolutionSigDigs == sResolution ||
+         10 * sResolutionSigDigs > sResolution);
+       sResolutionSigDigs *= 10);
+
+  gInitialized = true;
+
+  return;
+}
+
+void
+TimeStamp::Shutdown()
+{
+}
+
+TimeStamp
+TimeStamp::Now(bool aHighResolution)
+{
+  return TimeStamp(ClockTime());
+}
+
+// Computes and returns the process uptime in microseconds.
+// Returns 0 if an error was encountered.
+
+uint64_t
+TimeStamp::ComputeProcessUptime()
+{
+  struct timeval tv;
+  int rv = gettimeofday(&tv, nullptr);
+
+  if (rv == -1) {
+    return 0;
+  }
+
+  int mib[] = {
+    CTL_KERN,
+    KERN_PROC,
+    KERN_PROC_PID,
+    getpid(),
+  };
+  u_int mibLen = sizeof(mib) / sizeof(mib[0]);
+
+  struct kinfo_proc proc;
+  size_t bufferSize = sizeof(proc);
+  rv = sysctl(mib, mibLen, &proc, &bufferSize, nullptr, 0);
+
+  if (rv == -1) {
+    return 0;
+  }
+
+  uint64_t startTime =
+    ((uint64_t)proc.kp_proc.p_un.__p_starttime.tv_sec * kUsPerSec) +
+    proc.kp_proc.p_un.__p_starttime.tv_usec;
+  uint64_t now = (tv.tv_sec * kUsPerSec) + tv.tv_usec;
+
+  if (startTime > now) {
+    return 0;
+  }
+
+  return now - startTime;
+}
+
+} // namespace mozilla
diff --git a/mozglue/misc/TimeStamp_posix.cpp b/mozglue/misc/TimeStamp_posix.cpp
new file mode 100644
index 000000000..05deddea4
--- /dev/null
+++ b/mozglue/misc/TimeStamp_posix.cpp
@@ -0,0 +1,362 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//
+// Implement TimeStamp::Now() with POSIX clocks.
+//
+// The "tick" unit for POSIX clocks is simply a nanosecond, as this is
+// the smallest unit of time representable by struct timespec.  That
+// doesn't mean that a nanosecond is the resolution of TimeDurations
+// obtained with this API; see TimeDuration::Resolution;
+//
+
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+#include <string.h>
+
+#if defined(__DragonFly__) || defined(__FreeBSD__) \
+    || defined(__NetBSD__) || defined(__OpenBSD__)
+#include <sys/param.h>
+#include <sys/sysctl.h>
+#endif
+
+#if defined(__DragonFly__) || defined(__FreeBSD__)
+#include <sys/user.h>
+#endif
+
+#if defined(__NetBSD__)
+#undef KERN_PROC
+#define KERN_PROC KERN_PROC2
+#define KINFO_PROC struct kinfo_proc2
+#else
+#define KINFO_PROC struct kinfo_proc
+#endif
+
+#if defined(__DragonFly__)
+#define KP_START_SEC kp_start.tv_sec
+#define KP_START_USEC kp_start.tv_usec
+#elif defined(__FreeBSD__)
+#define KP_START_SEC ki_start.tv_sec
+#define KP_START_USEC ki_start.tv_usec
+#else
+#define KP_START_SEC p_ustart_sec
+#define KP_START_USEC p_ustart_usec
+#endif
+
+#include "mozilla/Sprintf.h"
+#include "mozilla/TimeStamp.h"
+#include <pthread.h>
+
+// Estimate of the smallest duration of time we can measure.
+static uint64_t sResolution;
+static uint64_t sResolutionSigDigs;
+
+static const uint16_t kNsPerUs   =       1000;
+static const uint64_t kNsPerMs   =    1000000;
+static const uint64_t kNsPerSec  = 1000000000;
+static const double kNsPerMsd    =    1000000.0;
+static const double kNsPerSecd   = 1000000000.0;
+
+static uint64_t
+TimespecToNs(const struct timespec& aTs)
+{
+  uint64_t baseNs = uint64_t(aTs.tv_sec) * kNsPerSec;
+  return baseNs + uint64_t(aTs.tv_nsec);
+}
+
+static uint64_t
+ClockTimeNs()
+{
+  struct timespec ts;
+  // this can't fail: we know &ts is valid, and TimeStamp::Startup()
+  // checks that CLOCK_MONOTONIC is supported (and aborts if not)
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+
+  // tv_sec is defined to be relative to an arbitrary point in time,
+  // but it would be madness for that point in time to be earlier than
+  // the Epoch.  So we can safely assume that even if time_t is 32
+  // bits, tv_sec won't overflow while the browser is open.  Revisit
+  // this argument if we're still building with 32-bit time_t around
+  // the year 2037.
+  return TimespecToNs(ts);
+}
+
+static uint64_t
+ClockResolutionNs()
+{
+  // NB: why not rely on clock_getres()?  Two reasons: (i) it might
+  // lie, and (ii) it might return an "ideal" resolution that while
+  // theoretically true, could never be measured in practice.  Since
+  // clock_gettime() likely involves a system call on your platform,
+  // the "actual" timing resolution shouldn't be lower than syscall
+  // overhead.
+
+  uint64_t start = ClockTimeNs();
+  uint64_t end = ClockTimeNs();
+  uint64_t minres = (end - start);
+
+  // 10 total trials is arbitrary: what we're trying to avoid by
+  // looping is getting unlucky and being interrupted by a context
+  // switch or signal, or being bitten by paging/cache effects
+  for (int i = 0; i < 9; ++i) {
+    start = ClockTimeNs();
+    end = ClockTimeNs();
+
+    uint64_t candidate = (start - end);
+    if (candidate < minres) {
+      minres = candidate;
+    }
+  }
+
+  if (0 == minres) {
+    // measurable resolution is either incredibly low, ~1ns, or very
+    // high.  fall back on clock_getres()
+    struct timespec ts;
+    if (0 == clock_getres(CLOCK_MONOTONIC, &ts)) {
+      minres = TimespecToNs(ts);
+    }
+  }
+
+  if (0 == minres) {
+    // clock_getres probably failed.  fall back on NSPR's resolution
+    // assumption
+    minres = 1 * kNsPerMs;
+  }
+
+  return minres;
+}
+
+namespace mozilla {
+
+double
+BaseTimeDurationPlatformUtils::ToSeconds(int64_t aTicks)
+{
+  return double(aTicks) / kNsPerSecd;
+}
+
+double
+BaseTimeDurationPlatformUtils::ToSecondsSigDigits(int64_t aTicks)
+{
+  // don't report a value < mResolution ...
+  int64_t valueSigDigs = sResolution * (aTicks / sResolution);
+  // and chop off insignificant digits
+  valueSigDigs = sResolutionSigDigs * (valueSigDigs / sResolutionSigDigs);
+  return double(valueSigDigs) / kNsPerSecd;
+}
+
+int64_t
+BaseTimeDurationPlatformUtils::TicksFromMilliseconds(double aMilliseconds)
+{
+  double result = aMilliseconds * kNsPerMsd;
+  if (result > INT64_MAX) {
+    return INT64_MAX;
+  } else if (result < INT64_MIN) {
+    return INT64_MIN;
+  }
+
+  return result;
+}
+
+int64_t
+BaseTimeDurationPlatformUtils::ResolutionInTicks()
+{
+  return static_cast<int64_t>(sResolution);
+}
+
+static bool gInitialized = false;
+
+void
+TimeStamp::Startup()
+{
+  if (gInitialized) {
+    return;
+  }
+
+  struct timespec dummy;
+  if (clock_gettime(CLOCK_MONOTONIC, &dummy) != 0) {
+    MOZ_CRASH("CLOCK_MONOTONIC is absent!");
+  }
+
+  sResolution = ClockResolutionNs();
+
+  // find the number of significant digits in sResolution, for the
+  // sake of ToSecondsSigDigits()
+  for (sResolutionSigDigs = 1;
+       !(sResolutionSigDigs == sResolution ||
+         10 * sResolutionSigDigs > sResolution);
+       sResolutionSigDigs *= 10);
+
+  gInitialized = true;
+
+  return;
+}
+
+void
+TimeStamp::Shutdown()
+{
+}
+
+TimeStamp
+TimeStamp::Now(bool aHighResolution)
+{
+  return TimeStamp(ClockTimeNs());
+}
+
+#if defined(XP_LINUX) || defined(ANDROID)
+
+// Calculates the amount of jiffies that have elapsed since boot and up to the
+// starttime value of a specific process as found in its /proc/*/stat file.
+// Returns 0 if an error occurred.
+
+static uint64_t
+JiffiesSinceBoot(const char* aFile)
+{
+  char stat[512];
+
+  FILE* f = fopen(aFile, "r");
+  if (!f) {
+    return 0;
+  }
+
+  int n = fread(&stat, 1, sizeof(stat) - 1, f);
+
+  fclose(f);
+
+  if (n <= 0) {
+    return 0;
+  }
+
+  stat[n] = 0;
+
+  long long unsigned startTime = 0; // instead of uint64_t to keep GCC quiet
+  char* s = strrchr(stat, ')');
+
+  if (!s) {
+    return 0;
+  }
+
+  int rv = sscanf(s + 2,
+                  "%*c %*d %*d %*d %*d %*d %*u %*u %*u %*u "
+                  "%*u %*u %*u %*d %*d %*d %*d %*d %*d %llu",
+                  &startTime);
+
+  if (rv != 1 || !startTime) {
+    return 0;
+  }
+
+  return startTime;
+}
+
+// Computes the interval that has elapsed between the thread creation and the
+// process creation by comparing the starttime fields in the respective
+// /proc/*/stat files. The resulting value will be a good approximation of the
+// process uptime. This value will be stored at the address pointed by aTime;
+// if an error occurred 0 will be stored instead.
+
+static void*
+ComputeProcessUptimeThread(void* aTime)
+{
+  uint64_t* uptime = static_cast<uint64_t*>(aTime);
+  long hz = sysconf(_SC_CLK_TCK);
+
+  *uptime = 0;
+
+  if (!hz) {
+    return nullptr;
+  }
+
+  char threadStat[40];
+  SprintfLiteral(threadStat, "/proc/self/task/%d/stat", (pid_t)syscall(__NR_gettid));
+
+  uint64_t threadJiffies = JiffiesSinceBoot(threadStat);
+  uint64_t selfJiffies = JiffiesSinceBoot("/proc/self/stat");
+
+  if (!threadJiffies || !selfJiffies) {
+    return nullptr;
+  }
+
+  *uptime = ((threadJiffies - selfJiffies) * kNsPerSec) / hz;
+  return nullptr;
+}
+
+// Computes and returns the process uptime in us on Linux & its derivatives.
+// Returns 0 if an error was encountered.
+
+uint64_t
+TimeStamp::ComputeProcessUptime()
+{
+  uint64_t uptime = 0;
+  pthread_t uptime_pthread;
+
+  if (pthread_create(&uptime_pthread, nullptr, ComputeProcessUptimeThread, &uptime)) {
+    MOZ_CRASH("Failed to create process uptime thread.");
+    return 0;
+  }
+
+  pthread_join(uptime_pthread, NULL);
+
+  return uptime / kNsPerUs;
+}
+
+#elif defined(__DragonFly__) || defined(__FreeBSD__) \
+      || defined(__NetBSD__) || defined(__OpenBSD__)
+
+// Computes and returns the process uptime in us on various BSD flavors.
+// Returns 0 if an error was encountered.
+
+uint64_t
+TimeStamp::ComputeProcessUptime()
+{
+  struct timespec ts;
+  int rv = clock_gettime(CLOCK_REALTIME, &ts);
+
+  if (rv == -1) {
+    return 0;
+  }
+
+  int mib[] = {
+    CTL_KERN,
+    KERN_PROC,
+    KERN_PROC_PID,
+    getpid(),
+#if defined(__NetBSD__) || defined(__OpenBSD__)
+    sizeof(KINFO_PROC),
+    1,
+#endif
+  };
+  u_int mibLen = sizeof(mib) / sizeof(mib[0]);
+
+  KINFO_PROC proc;
+  size_t bufferSize = sizeof(proc);
+  rv = sysctl(mib, mibLen, &proc, &bufferSize, nullptr, 0);
+
+  if (rv == -1) {
+    return 0;
+  }
+
+  uint64_t startTime = ((uint64_t)proc.KP_START_SEC * kNsPerSec) +
+    (proc.KP_START_USEC * kNsPerUs);
+  uint64_t now = ((uint64_t)ts.tv_sec * kNsPerSec) + ts.tv_nsec;
+
+  if (startTime > now) {
+    return 0;
+  }
+
+  return (now - startTime) / kNsPerUs;
+}
+
+#else
+
+uint64_t
+TimeStamp::ComputeProcessUptime()
+{
+  return 0;
+}
+
+#endif
+
+} // namespace mozilla
diff --git a/mozglue/misc/TimeStamp_windows.cpp b/mozglue/misc/TimeStamp_windows.cpp
new file mode 100644
index 000000000..cd519affd
--- /dev/null
+++ b/mozglue/misc/TimeStamp_windows.cpp
@@ -0,0 +1,576 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Implement TimeStamp::Now() with QueryPerformanceCounter() controlled with
+// values of GetTickCount().
+
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/TimeStamp.h"
+
+#include <stdio.h>
+#include <intrin.h>
+#include <windows.h>
+
+// To enable logging define to your favorite logging API
+#define LOG(x)
+
+class AutoCriticalSection
+{
+public:
+  AutoCriticalSection(LPCRITICAL_SECTION aSection)
+    : mSection(aSection)
+  {
+    ::EnterCriticalSection(mSection);
+  }
+  ~AutoCriticalSection()
+  {
+    ::LeaveCriticalSection(mSection);
+  }
+private:
+  LPCRITICAL_SECTION mSection;
+};
+
+// Estimate of the smallest duration of time we can measure.
+static volatile ULONGLONG sResolution;
+static volatile ULONGLONG sResolutionSigDigs;
+static const double   kNsPerSecd  = 1000000000.0;
+static const LONGLONG kNsPerMillisec = 1000000;
+
+// ----------------------------------------------------------------------------
+// Global constants
+// ----------------------------------------------------------------------------
+
+// Tolerance to failures settings.
+//
+// What is the interval we want to have failure free.
+// in [ms]
+static const uint32_t kFailureFreeInterval = 5000;
+// How many failures we are willing to tolerate in the interval.
+static const uint32_t kMaxFailuresPerInterval = 4;
+// What is the threshold to treat fluctuations as actual failures.
+// in [ms]
+static const uint32_t kFailureThreshold = 50;
+
+// If we are not able to get the value of GTC time increment, use this value
+// which is the most usual increment.
+static const DWORD kDefaultTimeIncrement = 156001;
+
+// ----------------------------------------------------------------------------
+// Global variables, not changing at runtime
+// ----------------------------------------------------------------------------
+
+/**
+ * The [mt] unit:
+ *
+ * Many values are kept in ticks of the Performance Coutner x 1000,
+ * further just referred as [mt], meaning milli-ticks.
+ *
+ * This is needed to preserve maximum precision of the performance frequency
+ * representation.  GetTickCount values in milliseconds are multiplied with
+ * frequency per second.  Therefor we need to multiply QPC value by 1000 to
+ * have the same units to allow simple arithmentic with both QPC and GTC.
+ */
+
+#define ms2mt(x) ((x) * sFrequencyPerSec)
+#define mt2ms(x) ((x) / sFrequencyPerSec)
+#define mt2ms_f(x) (double(x) / sFrequencyPerSec)
+
+// Result of QueryPerformanceFrequency
+static LONGLONG sFrequencyPerSec = 0;
+
+// How much we are tolerant to GTC occasional loose of resoltion.
+// This number says how many multiples of the minimal GTC resolution
+// detected on the system are acceptable.  This number is empirical.
+static const LONGLONG kGTCTickLeapTolerance = 4;
+
+// Base tolerance (more: "inability of detection" range) threshold is calculated
+// dynamically, and kept in sGTCResulutionThreshold.
+//
+// Schematically, QPC worked "100%" correctly if ((GTC_now - GTC_epoch) -
+// (QPC_now - QPC_epoch)) was in  [-sGTCResulutionThreshold, sGTCResulutionThreshold]
+// interval every time we'd compared two time stamps.
+// If not, then we check the overflow behind this basic threshold
+// is in kFailureThreshold.  If not, we condider it as a QPC failure.  If too many
+// failures in short time are detected, QPC is considered faulty and disabled.
+//
+// Kept in [mt]
+static LONGLONG sGTCResulutionThreshold;
+
+// If QPC is found faulty for two stamps in this interval, we engage
+// the fault detection algorithm.  For duration larger then this limit
+// we bypass using durations calculated from QPC when jitter is detected,
+// but don't touch the sUseQPC flag.
+//
+// Value is in [ms].
+static const uint32_t kHardFailureLimit = 2000;
+// Conversion to [mt]
+static LONGLONG sHardFailureLimit;
+
+// Conversion of kFailureFreeInterval and kFailureThreshold to [mt]
+static LONGLONG sFailureFreeInterval;
+static LONGLONG sFailureThreshold;
+
+// ----------------------------------------------------------------------------
+// Systemm status flags
+// ----------------------------------------------------------------------------
+
+// Flag for stable TSC that indicates platform where QPC is stable.
+static bool sHasStableTSC = false;
+
+// ----------------------------------------------------------------------------
+// Global state variables, changing at runtime
+// ----------------------------------------------------------------------------
+
+// Initially true, set to false when QPC is found unstable and never
+// returns back to true since that time.
+static bool volatile sUseQPC = true;
+
+// ----------------------------------------------------------------------------
+// Global lock
+// ----------------------------------------------------------------------------
+
+// Thread spin count before entering the full wait state for sTimeStampLock.
+// Inspired by Rob Arnold's work on PRMJ_Now().
+static const DWORD kLockSpinCount = 4096;
+
+// Common mutex (thanks the relative complexity of the logic, this is better
+// then using CMPXCHG8B.)
+// It is protecting the globals bellow.
+static CRITICAL_SECTION sTimeStampLock;
+
+// ----------------------------------------------------------------------------
+// Global lock protected variables
+// ----------------------------------------------------------------------------
+
+// Timestamp in future until QPC must behave correctly.
+// Set to now + kFailureFreeInterval on first QPC failure detection.
+// Set to now + E * kFailureFreeInterval on following errors,
+//   where E is number of errors detected during last kFailureFreeInterval
+//   milliseconds, calculated simply as:
+//   E = (sFaultIntoleranceCheckpoint - now) / kFailureFreeInterval + 1.
+// When E > kMaxFailuresPerInterval -> disable QPC.
+//
+// Kept in [mt]
+static ULONGLONG sFaultIntoleranceCheckpoint = 0;
+
+// Used only when GetTickCount64 is not available on the platform.
+// Last result of GetTickCount call.
+//
+// Kept in [ms]
+static DWORD sLastGTCResult = 0;
+
+// Higher part of the 64-bit value of MozGetTickCount64,
+// incremented atomically.
+static DWORD sLastGTCRollover = 0;
+
+namespace mozilla {
+
+typedef ULONGLONG (WINAPI* GetTickCount64_t)();
+static GetTickCount64_t sGetTickCount64 = nullptr;
+
+// Function protecting GetTickCount result from rolling over,
+// result is in [ms]
+static ULONGLONG WINAPI
+MozGetTickCount64()
+{
+  DWORD GTC = ::GetTickCount();
+
+  // Cheaper then CMPXCHG8B
+  AutoCriticalSection lock(&sTimeStampLock);
+
+  // Pull the rollover counter forward only if new value of GTC goes way
+  // down under the last saved result
+  if ((sLastGTCResult > GTC) && ((sLastGTCResult - GTC) > (1UL << 30))) {
+    ++sLastGTCRollover;
+  }
+
+  sLastGTCResult = GTC;
+  return ULONGLONG(sLastGTCRollover) << 32 | sLastGTCResult;
+}
+
+// Result is in [mt]
+static inline ULONGLONG
+PerformanceCounter()
+{
+  LARGE_INTEGER pc;
+  ::QueryPerformanceCounter(&pc);
+  return pc.QuadPart * 1000ULL;
+}
+
+static void
+InitThresholds()
+{
+  DWORD timeAdjustment = 0, timeIncrement = 0;
+  BOOL timeAdjustmentDisabled;
+  GetSystemTimeAdjustment(&timeAdjustment,
+                          &timeIncrement,
+                          &timeAdjustmentDisabled);
+
+  LOG(("TimeStamp: timeIncrement=%d [100ns]", timeIncrement));
+
+  if (!timeIncrement) {
+    timeIncrement = kDefaultTimeIncrement;
+  }
+
+  // Ceiling to a millisecond
+  // Example values: 156001, 210000
+  DWORD timeIncrementCeil = timeIncrement;
+  // Don't want to round up if already rounded, values will be: 156000, 209999
+  timeIncrementCeil -= 1;
+  // Convert to ms, values will be: 15, 20
+  timeIncrementCeil /= 10000;
+  // Round up, values will be: 16, 21
+  timeIncrementCeil += 1;
+  // Convert back to 100ns, values will be: 160000, 210000
+  timeIncrementCeil *= 10000;
+
+  // How many milli-ticks has the interval rounded up
+  LONGLONG ticksPerGetTickCountResolutionCeiling =
+    (int64_t(timeIncrementCeil) * sFrequencyPerSec) / 10000LL;
+
+  // GTC may jump by 32 (2*16) ms in two steps, therefor use the ceiling value.
+  sGTCResulutionThreshold =
+    LONGLONG(kGTCTickLeapTolerance * ticksPerGetTickCountResolutionCeiling);
+
+  sHardFailureLimit = ms2mt(kHardFailureLimit);
+  sFailureFreeInterval = ms2mt(kFailureFreeInterval);
+  sFailureThreshold = ms2mt(kFailureThreshold);
+}
+
+static void
+InitResolution()
+{
+  // 10 total trials is arbitrary: what we're trying to avoid by
+  // looping is getting unlucky and being interrupted by a context
+  // switch or signal, or being bitten by paging/cache effects
+
+  ULONGLONG minres = ~0ULL;
+  int loops = 10;
+  do {
+    ULONGLONG start = PerformanceCounter();
+    ULONGLONG end = PerformanceCounter();
+
+    ULONGLONG candidate = (end - start);
+    if (candidate < minres) {
+      minres = candidate;
+    }
+  } while (--loops && minres);
+
+  if (0 == minres) {
+    minres = 1;
+  }
+
+  // Converting minres that is in [mt] to nanosecods, multiplicating
+  // the argument to preserve resolution.
+  ULONGLONG result = mt2ms(minres * kNsPerMillisec);
+  if (0 == result) {
+    result = 1;
+  }
+
+  sResolution = result;
+
+  // find the number of significant digits in mResolution, for the
+  // sake of ToSecondsSigDigits()
+  ULONGLONG sigDigs;
+  for (sigDigs = 1;
+       !(sigDigs == result || 10 * sigDigs > result);
+       sigDigs *= 10);
+
+  sResolutionSigDigs = sigDigs;
+}
+
+// ----------------------------------------------------------------------------
+// TimeStampValue implementation
+// ----------------------------------------------------------------------------
+MFBT_API
+TimeStampValue::TimeStampValue(ULONGLONG aGTC, ULONGLONG aQPC, bool aHasQPC)
+  : mGTC(aGTC)
+  , mQPC(aQPC)
+  , mHasQPC(aHasQPC)
+  , mIsNull(false)
+{
+}
+
+MFBT_API TimeStampValue&
+TimeStampValue::operator+=(const int64_t aOther)
+{
+  mGTC += aOther;
+  mQPC += aOther;
+  return *this;
+}
+
+MFBT_API TimeStampValue&
+TimeStampValue::operator-=(const int64_t aOther)
+{
+  mGTC -= aOther;
+  mQPC -= aOther;
+  return *this;
+}
+
+// If the duration is less then two seconds, perform check of QPC stability
+// by comparing both GTC and QPC calculated durations of this and aOther.
+MFBT_API uint64_t
+TimeStampValue::CheckQPC(const TimeStampValue& aOther) const
+{
+  uint64_t deltaGTC = mGTC - aOther.mGTC;
+
+  if (!mHasQPC || !aOther.mHasQPC) { // Both not holding QPC
+    return deltaGTC;
+  }
+
+  uint64_t deltaQPC = mQPC - aOther.mQPC;
+
+  if (sHasStableTSC) { // For stable TSC there is no need to check
+    return deltaQPC;
+  }
+
+  // Check QPC is sane before using it.
+  int64_t diff = DeprecatedAbs(int64_t(deltaQPC) - int64_t(deltaGTC));
+  if (diff <= sGTCResulutionThreshold) {
+    return deltaQPC;
+  }
+
+  // Treat absolutely for calibration purposes
+  int64_t duration = DeprecatedAbs(int64_t(deltaGTC));
+  int64_t overflow = diff - sGTCResulutionThreshold;
+
+  LOG(("TimeStamp: QPC check after %llums with overflow %1.4fms",
+       mt2ms(duration), mt2ms_f(overflow)));
+
+  if (overflow <= sFailureThreshold) {  // We are in the limit, let go.
+    return deltaQPC;
+  }
+
+  // QPC deviates, don't use it, since now this method may only return deltaGTC.
+
+  if (!sUseQPC) { // QPC already disabled, no need to run the fault tolerance algorithm.
+    return deltaGTC;
+  }
+
+  LOG(("TimeStamp: QPC jittered over failure threshold"));
+
+  if (duration < sHardFailureLimit) {
+    // Interval between the two time stamps is very short, consider
+    // QPC as unstable and record a failure.
+    uint64_t now = ms2mt(sGetTickCount64());
+
+    AutoCriticalSection lock(&sTimeStampLock);
+
+    if (sFaultIntoleranceCheckpoint && sFaultIntoleranceCheckpoint > now) {
+      // There's already been an error in the last fault intollerant interval.
+      // Time since now to the checkpoint actually holds information on how many
+      // failures there were in the failure free interval we have defined.
+      uint64_t failureCount =
+        (sFaultIntoleranceCheckpoint - now + sFailureFreeInterval - 1) /
+        sFailureFreeInterval;
+      if (failureCount > kMaxFailuresPerInterval) {
+        sUseQPC = false;
+        LOG(("TimeStamp: QPC disabled"));
+      } else {
+        // Move the fault intolerance checkpoint more to the future, prolong it
+        // to reflect the number of detected failures.
+        ++failureCount;
+        sFaultIntoleranceCheckpoint = now + failureCount * sFailureFreeInterval;
+        LOG(("TimeStamp: recording %dth QPC failure", failureCount));
+      }
+    } else {
+      // Setup fault intolerance checkpoint in the future for first detected error.
+      sFaultIntoleranceCheckpoint = now + sFailureFreeInterval;
+      LOG(("TimeStamp: recording 1st QPC failure"));
+    }
+  }
+
+  return deltaGTC;
+}
+
+MFBT_API uint64_t
+TimeStampValue::operator-(const TimeStampValue& aOther) const
+{
+  if (mIsNull && aOther.mIsNull) {
+    return uint64_t(0);
+  }
+
+  return CheckQPC(aOther);
+}
+
+// ----------------------------------------------------------------------------
+// TimeDuration and TimeStamp implementation
+// ----------------------------------------------------------------------------
+
+MFBT_API double
+BaseTimeDurationPlatformUtils::ToSeconds(int64_t aTicks)
+{
+  // Converting before arithmetic avoids blocked store forward
+  return double(aTicks) / (double(sFrequencyPerSec) * 1000.0);
+}
+
+MFBT_API double
+BaseTimeDurationPlatformUtils::ToSecondsSigDigits(int64_t aTicks)
+{
+  // don't report a value < mResolution ...
+  LONGLONG resolution = sResolution;
+  LONGLONG resolutionSigDigs = sResolutionSigDigs;
+  LONGLONG valueSigDigs = resolution * (aTicks / resolution);
+  // and chop off insignificant digits
+  valueSigDigs = resolutionSigDigs * (valueSigDigs / resolutionSigDigs);
+  return double(valueSigDigs) / kNsPerSecd;
+}
+
+MFBT_API int64_t
+BaseTimeDurationPlatformUtils::TicksFromMilliseconds(double aMilliseconds)
+{
+  double result = ms2mt(aMilliseconds);
+  if (result > INT64_MAX) {
+    return INT64_MAX;
+  } else if (result < INT64_MIN) {
+    return INT64_MIN;
+  }
+
+  return result;
+}
+
+MFBT_API int64_t
+BaseTimeDurationPlatformUtils::ResolutionInTicks()
+{
+  return static_cast<int64_t>(sResolution);
+}
+
+static bool
+HasStableTSC()
+{
+  union
+  {
+    int regs[4];
+    struct
+    {
+      int nIds;
+      char cpuString[12];
+    };
+  } cpuInfo;
+
+  __cpuid(cpuInfo.regs, 0);
+  // Only allow Intel CPUs for now
+  // The order of the registers is reg[1], reg[3], reg[2].  We just adjust the
+  // string so that we can compare in one go.
+  if (_strnicmp(cpuInfo.cpuString, "GenuntelineI",
+                sizeof(cpuInfo.cpuString))) {
+    return false;
+  }
+
+  int regs[4];
+
+  // detect if the Advanced Power Management feature is supported
+  __cpuid(regs, 0x80000000);
+  if (regs[0] < 0x80000007) {
+    return false;
+  }
+
+  __cpuid(regs, 0x80000007);
+  // if bit 8 is set than TSC will run at a constant rate
+  // in all ACPI P-state, C-states and T-states
+  return regs[3] & (1 << 8);
+}
+
+static bool gInitialized = false;
+
+MFBT_API void
+TimeStamp::Startup()
+{
+  if (gInitialized) {
+    return;
+  }
+
+  gInitialized = true;
+
+  // Decide which implementation to use for the high-performance timer.
+
+  HMODULE kernelDLL = GetModuleHandleW(L"kernel32.dll");
+  sGetTickCount64 = reinterpret_cast<GetTickCount64_t>(
+    GetProcAddress(kernelDLL, "GetTickCount64"));
+  if (!sGetTickCount64) {
+    // If the platform does not support the GetTickCount64 (Windows XP doesn't),
+    // then use our fallback implementation based on GetTickCount.
+    sGetTickCount64 = MozGetTickCount64;
+  }
+
+  InitializeCriticalSectionAndSpinCount(&sTimeStampLock, kLockSpinCount);
+
+  sHasStableTSC = HasStableTSC();
+  LOG(("TimeStamp: HasStableTSC=%d", sHasStableTSC));
+
+  LARGE_INTEGER freq;
+  sUseQPC = ::QueryPerformanceFrequency(&freq);
+  if (!sUseQPC) {
+    // No Performance Counter.  Fall back to use GetTickCount.
+    InitResolution();
+
+    LOG(("TimeStamp: using GetTickCount"));
+    return;
+  }
+
+  sFrequencyPerSec = freq.QuadPart;
+  LOG(("TimeStamp: QPC frequency=%llu", sFrequencyPerSec));
+
+  InitThresholds();
+  InitResolution();
+
+  return;
+}
+
+MFBT_API void
+TimeStamp::Shutdown()
+{
+  DeleteCriticalSection(&sTimeStampLock);
+}
+
+MFBT_API TimeStamp
+TimeStamp::Now(bool aHighResolution)
+{
+  // sUseQPC is volatile
+  bool useQPC = (aHighResolution && sUseQPC);
+
+  // Both values are in [mt] units.
+  ULONGLONG QPC = useQPC ? PerformanceCounter() : uint64_t(0);
+  ULONGLONG GTC = ms2mt(sGetTickCount64());
+  return TimeStamp(TimeStampValue(GTC, QPC, useQPC));
+}
+
+// Computes and returns the process uptime in microseconds.
+// Returns 0 if an error was encountered.
+
+MFBT_API uint64_t
+TimeStamp::ComputeProcessUptime()
+{
+  SYSTEMTIME nowSys;
+  GetSystemTime(&nowSys);
+
+  FILETIME now;
+  bool success = SystemTimeToFileTime(&nowSys, &now);
+
+  if (!success) {
+    return 0;
+  }
+
+  FILETIME start, foo, bar, baz;
+  success = GetProcessTimes(GetCurrentProcess(), &start, &foo, &bar, &baz);
+
+  if (!success) {
+    return 0;
+  }
+
+  ULARGE_INTEGER startUsec = {{
+     start.dwLowDateTime,
+     start.dwHighDateTime
+  }};
+  ULARGE_INTEGER nowUsec = {{
+    now.dwLowDateTime,
+    now.dwHighDateTime
+  }};
+
+  return (nowUsec.QuadPart - startUsec.QuadPart) / 10ULL;
+}
+
+} // namespace mozilla
diff --git a/mozglue/misc/TimeStamp_windows.h b/mozglue/misc/TimeStamp_windows.h
new file mode 100644
index 000000000..c87d34efc
--- /dev/null
+++ b/mozglue/misc/TimeStamp_windows.h
@@ -0,0 +1,83 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_TimeStamp_windows_h
+#define mozilla_TimeStamp_windows_h
+
+#include "mozilla/Types.h"
+
+namespace mozilla {
+
+class TimeStamp;
+
+class TimeStampValue
+{
+  friend struct IPC::ParamTraits<mozilla::TimeStampValue>;
+  friend class TimeStamp;
+  friend void StartupTimelineRecordExternal(int, uint64_t);
+
+  // Both QPC and GTC are kept in [mt] units.
+  uint64_t mGTC;
+  uint64_t mQPC;
+  bool mHasQPC;
+  bool mIsNull;
+
+  MFBT_API TimeStampValue(uint64_t aGTC, uint64_t aQPC, bool aHasQPC);
+
+  MFBT_API uint64_t CheckQPC(const TimeStampValue& aOther) const;
+
+  struct _SomethingVeryRandomHere;
+  constexpr TimeStampValue(_SomethingVeryRandomHere* aNullValue)
+    : mGTC(0)
+    , mQPC(0)
+    , mHasQPC(false)
+    , mIsNull(true)
+  {
+  }
+
+public:
+  MFBT_API uint64_t operator-(const TimeStampValue& aOther) const;
+
+  TimeStampValue operator+(const int64_t aOther) const
+  {
+    return TimeStampValue(mGTC + aOther, mQPC + aOther, mHasQPC);
+  }
+  TimeStampValue operator-(const int64_t aOther) const
+  {
+    return TimeStampValue(mGTC - aOther, mQPC - aOther, mHasQPC);
+  }
+  MFBT_API TimeStampValue& operator+=(const int64_t aOther);
+  MFBT_API TimeStampValue& operator-=(const int64_t aOther);
+
+  bool operator<(const TimeStampValue& aOther) const
+  {
+    return int64_t(*this - aOther) < 0;
+  }
+  bool operator>(const TimeStampValue& aOther) const
+  {
+    return int64_t(*this - aOther) > 0;
+  }
+  bool operator<=(const TimeStampValue& aOther) const
+  {
+    return int64_t(*this - aOther) <= 0;
+  }
+  bool operator>=(const TimeStampValue& aOther) const
+  {
+    return int64_t(*this - aOther) >= 0;
+  }
+  bool operator==(const TimeStampValue& aOther) const
+  {
+    return int64_t(*this - aOther) == 0;
+  }
+  bool operator!=(const TimeStampValue& aOther) const
+  {
+    return int64_t(*this - aOther) != 0;
+  }
+};
+
+}
+
+#endif /* mozilla_TimeStamp_h */
diff --git a/mozglue/misc/moz.build b/mozglue/misc/moz.build
new file mode 100644
index 000000000..9c2ef399c
--- /dev/null
+++ b/mozglue/misc/moz.build
@@ -0,0 +1,37 @@
+FINAL_LIBRARY = 'mozglue'
+
+EXPORTS.mozilla += [
+    'StackWalk.h',
+    'TimeStamp.h',
+]
+
+if CONFIG['OS_ARCH'] == 'WINNT':
+    EXPORTS.mozilla += [
+        'StackWalk_windows.h',
+        'TimeStamp_windows.h',
+    ]
+
+SOURCES += [
+    'StackWalk.cpp',
+    'TimeStamp.cpp',
+]
+
+OS_LIBS += CONFIG['REALTIME_LIBS']
+
+DEFINES['IMPL_MFBT'] = True
+
+if CONFIG['OS_ARCH'] == 'WINNT':
+    SOURCES += [
+        'TimeStamp_windows.cpp',
+    ]
+    OS_LIBS += ['dbghelp']
+elif CONFIG['HAVE_CLOCK_MONOTONIC']:
+    SOURCES += [
+        'TimeStamp_posix.cpp',
+    ]
+elif CONFIG['OS_ARCH'] == 'Darwin':
+    SOURCES += [
+        'TimeStamp_darwin.cpp',
+    ]
+elif CONFIG['COMPILE_ENVIRONMENT']:
+    error('No TimeStamp implementation on this platform.  Build will not succeed')