Add m-esr52 at 52.6.0

1 files changed, 1381 insertions, 0 deletions

diff --git a/widget/ContentCache.cpp b/widget/ContentCache.cpp
new file mode 100644
index 0000000000..52d62d5880
--- /dev/null
+++ b/widget/ContentCache.cpp
@@ -0,0 +1,1381 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* 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/. */
+
+#include "mozilla/ContentCache.h"
+#include "mozilla/IMEStateManager.h"
+#include "mozilla/Logging.h"
+#include "mozilla/TextComposition.h"
+#include "mozilla/TextEvents.h"
+#include "nsIWidget.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/Move.h"
+
+namespace mozilla {
+
+using namespace widget;
+
+static const char*
+GetBoolName(bool aBool)
+{
+  return aBool ? "true" : "false";
+}
+
+static const char*
+GetNotificationName(const IMENotification* aNotification)
+{
+  if (!aNotification) {
+    return "Not notification";
+  }
+  return ToChar(aNotification->mMessage);
+}
+
+class GetRectText : public nsAutoCString
+{
+public:
+  explicit GetRectText(const LayoutDeviceIntRect& aRect)
+  {
+    Assign("{ x=");
+    AppendInt(aRect.x);
+    Append(", y=");
+    AppendInt(aRect.y);
+    Append(", width=");
+    AppendInt(aRect.width);
+    Append(", height=");
+    AppendInt(aRect.height);
+    Append(" }");
+  }
+  virtual ~GetRectText() {}
+};
+
+class GetWritingModeName : public nsAutoCString
+{
+public:
+  explicit GetWritingModeName(const WritingMode& aWritingMode)
+  {
+    if (!aWritingMode.IsVertical()) {
+      Assign("Horizontal");
+      return;
+    }
+    if (aWritingMode.IsVerticalLR()) {
+      Assign("Vertical (LTR)");
+      return;
+    }
+    Assign("Vertical (RTL)");
+  }
+  virtual ~GetWritingModeName() {}
+};
+
+class GetEscapedUTF8String final : public NS_ConvertUTF16toUTF8
+{
+public:
+  explicit GetEscapedUTF8String(const nsAString& aString)
+    : NS_ConvertUTF16toUTF8(aString)
+  {
+    Escape();
+  }
+  explicit GetEscapedUTF8String(const char16ptr_t aString)
+    : NS_ConvertUTF16toUTF8(aString)
+  {
+    Escape();
+  }
+  GetEscapedUTF8String(const char16ptr_t aString, uint32_t aLength)
+    : NS_ConvertUTF16toUTF8(aString, aLength)
+  {
+    Escape();
+  }
+
+private:
+  void Escape()
+  {
+    ReplaceSubstring("\r", "\\r");
+    ReplaceSubstring("\n", "\\n");
+    ReplaceSubstring("\t", "\\t");
+  }
+};
+
+/*****************************************************************************
+ * mozilla::ContentCache
+ *****************************************************************************/
+
+LazyLogModule sContentCacheLog("ContentCacheWidgets");
+
+ContentCache::ContentCache()
+  : mCompositionStart(UINT32_MAX)
+{
+}
+
+/*****************************************************************************
+ * mozilla::ContentCacheInChild
+ *****************************************************************************/
+
+ContentCacheInChild::ContentCacheInChild()
+  : ContentCache()
+{
+}
+
+void
+ContentCacheInChild::Clear()
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p Clear()", this));
+
+  mCompositionStart = UINT32_MAX;
+  mText.Truncate();
+  mSelection.Clear();
+  mFirstCharRect.SetEmpty();
+  mCaret.Clear();
+  mTextRectArray.Clear();
+  mEditorRect.SetEmpty();
+}
+
+bool
+ContentCacheInChild::CacheAll(nsIWidget* aWidget,
+                              const IMENotification* aNotification)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheAll(aWidget=0x%p, aNotification=%s)",
+     this, aWidget, GetNotificationName(aNotification)));
+
+  if (NS_WARN_IF(!CacheText(aWidget, aNotification)) ||
+      NS_WARN_IF(!CacheEditorRect(aWidget, aNotification))) {
+    return false;
+  }
+  return true;
+}
+
+bool
+ContentCacheInChild::CacheSelection(nsIWidget* aWidget,
+                                    const IMENotification* aNotification)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheSelection(aWidget=0x%p, aNotification=%s)",
+     this, aWidget, GetNotificationName(aNotification)));
+
+  mCaret.Clear();
+  mSelection.Clear();
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  WidgetQueryContentEvent selection(true, eQuerySelectedText, aWidget);
+  aWidget->DispatchEvent(&selection, status);
+  if (NS_WARN_IF(!selection.mSucceeded)) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p CacheSelection(), FAILED, "
+       "couldn't retrieve the selected text", this));
+    return false;
+  }
+  if (selection.mReply.mReversed) {
+    mSelection.mAnchor =
+      selection.mReply.mOffset + selection.mReply.mString.Length();
+    mSelection.mFocus = selection.mReply.mOffset;
+  } else {
+    mSelection.mAnchor = selection.mReply.mOffset;
+    mSelection.mFocus =
+      selection.mReply.mOffset + selection.mReply.mString.Length();
+  }
+  mSelection.mWritingMode = selection.GetWritingMode();
+
+  return CacheCaret(aWidget, aNotification) &&
+         CacheTextRects(aWidget, aNotification);
+}
+
+bool
+ContentCacheInChild::CacheCaret(nsIWidget* aWidget,
+                                const IMENotification* aNotification)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheCaret(aWidget=0x%p, aNotification=%s)",
+     this, aWidget, GetNotificationName(aNotification)));
+
+  mCaret.Clear();
+
+  if (NS_WARN_IF(!mSelection.IsValid())) {
+    return false;
+  }
+
+  // XXX Should be mSelection.mFocus?
+  mCaret.mOffset = mSelection.StartOffset();
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  WidgetQueryContentEvent caretRect(true, eQueryCaretRect, aWidget);
+  caretRect.InitForQueryCaretRect(mCaret.mOffset);
+  aWidget->DispatchEvent(&caretRect, status);
+  if (NS_WARN_IF(!caretRect.mSucceeded)) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p CacheCaret(), FAILED, "
+       "couldn't retrieve the caret rect at offset=%u",
+       this, mCaret.mOffset));
+    mCaret.Clear();
+    return false;
+  }
+  mCaret.mRect = caretRect.mReply.mRect;
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheCaret(), Succeeded, "
+     "mSelection={ mAnchor=%u, mFocus=%u, mWritingMode=%s }, "
+     "mCaret={ mOffset=%u, mRect=%s }",
+     this, mSelection.mAnchor, mSelection.mFocus,
+     GetWritingModeName(mSelection.mWritingMode).get(), mCaret.mOffset,
+     GetRectText(mCaret.mRect).get()));
+  return true;
+}
+
+bool
+ContentCacheInChild::CacheEditorRect(nsIWidget* aWidget,
+                                     const IMENotification* aNotification)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheEditorRect(aWidget=0x%p, aNotification=%s)",
+     this, aWidget, GetNotificationName(aNotification)));
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  WidgetQueryContentEvent editorRectEvent(true, eQueryEditorRect, aWidget);
+  aWidget->DispatchEvent(&editorRectEvent, status);
+  if (NS_WARN_IF(!editorRectEvent.mSucceeded)) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p CacheEditorRect(), FAILED, "
+       "couldn't retrieve the editor rect", this));
+    return false;
+  }
+  mEditorRect = editorRectEvent.mReply.mRect;
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheEditorRect(), Succeeded, "
+     "mEditorRect=%s", this, GetRectText(mEditorRect).get()));
+  return true;
+}
+
+bool
+ContentCacheInChild::CacheText(nsIWidget* aWidget,
+                               const IMENotification* aNotification)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheText(aWidget=0x%p, aNotification=%s)",
+     this, aWidget, GetNotificationName(aNotification)));
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  WidgetQueryContentEvent queryText(true, eQueryTextContent, aWidget);
+  queryText.InitForQueryTextContent(0, UINT32_MAX);
+  aWidget->DispatchEvent(&queryText, status);
+  if (NS_WARN_IF(!queryText.mSucceeded)) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p CacheText(), FAILED, couldn't retrieve whole text", this));
+    mText.Truncate();
+    return false;
+  }
+  mText = queryText.mReply.mString;
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheText(), Succeeded, mText.Length()=%u", this, mText.Length()));
+
+  return CacheSelection(aWidget, aNotification);
+}
+
+bool
+ContentCacheInChild::QueryCharRect(nsIWidget* aWidget,
+                                   uint32_t aOffset,
+                                   LayoutDeviceIntRect& aCharRect) const
+{
+  aCharRect.SetEmpty();
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  WidgetQueryContentEvent textRect(true, eQueryTextRect, aWidget);
+  textRect.InitForQueryTextRect(aOffset, 1);
+  aWidget->DispatchEvent(&textRect, status);
+  if (NS_WARN_IF(!textRect.mSucceeded)) {
+    return false;
+  }
+  aCharRect = textRect.mReply.mRect;
+
+  // Guarantee the rect is not empty.
+  if (NS_WARN_IF(!aCharRect.height)) {
+    aCharRect.height = 1;
+  }
+  if (NS_WARN_IF(!aCharRect.width)) {
+    aCharRect.width = 1;
+  }
+  return true;
+}
+
+bool
+ContentCacheInChild::QueryCharRectArray(nsIWidget* aWidget,
+                                        uint32_t aOffset,
+                                        uint32_t aLength,
+                                        RectArray& aCharRectArray) const
+{
+  nsEventStatus status = nsEventStatus_eIgnore;
+  WidgetQueryContentEvent textRects(true, eQueryTextRectArray, aWidget);
+  textRects.InitForQueryTextRectArray(aOffset, aLength);
+  aWidget->DispatchEvent(&textRects, status);
+  if (NS_WARN_IF(!textRects.mSucceeded)) {
+    aCharRectArray.Clear();
+    return false;
+  }
+  aCharRectArray = Move(textRects.mReply.mRectArray);
+  return true;
+}
+
+bool
+ContentCacheInChild::CacheTextRects(nsIWidget* aWidget,
+                                    const IMENotification* aNotification)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheTextRects(aWidget=0x%p, aNotification=%s), "
+     "mCaret={ mOffset=%u, IsValid()=%s }",
+     this, aWidget, GetNotificationName(aNotification), mCaret.mOffset,
+     GetBoolName(mCaret.IsValid())));
+
+  mCompositionStart = UINT32_MAX;
+  mTextRectArray.Clear();
+  mSelection.ClearAnchorCharRects();
+  mSelection.ClearFocusCharRects();
+  mSelection.mRect.SetEmpty();
+  mFirstCharRect.SetEmpty();
+
+  if (NS_WARN_IF(!mSelection.IsValid())) {
+    return false;
+  }
+
+  // Retrieve text rects in composition string if there is.
+  RefPtr<TextComposition> textComposition =
+    IMEStateManager::GetTextCompositionFor(aWidget);
+  if (textComposition) {
+    // mCompositionStart may be updated by some composition event handlers.
+    // So, let's update it with the latest information.
+    mCompositionStart = textComposition->NativeOffsetOfStartComposition();
+    // Note that TextComposition::String() may not be modified here because
+    // it's modified after all edit action listeners are performed but this
+    // is called while some of them are performed.
+    uint32_t length = textComposition->LastData().Length();
+    mTextRectArray.mStart = mCompositionStart;
+    if (NS_WARN_IF(!QueryCharRectArray(aWidget, mTextRectArray.mStart, length,
+                                       mTextRectArray.mRects))) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p CacheTextRects(), FAILED, "
+         "couldn't retrieve text rect array of the composition string", this));
+    }
+  }
+
+  if (mTextRectArray.InRange(mSelection.mAnchor) &&
+      (!mSelection.mAnchor || mTextRectArray.InRange(mSelection.mAnchor - 1))) {
+    mSelection.mAnchorCharRects[eNextCharRect] =
+      mTextRectArray.GetRect(mSelection.mAnchor);
+    if (mSelection.mAnchor) {
+      mSelection.mAnchorCharRects[ePrevCharRect] =
+        mTextRectArray.GetRect(mSelection.mAnchor - 1);
+    }
+  } else {
+    RectArray rects;
+    uint32_t startOffset = mSelection.mAnchor ? mSelection.mAnchor - 1 : 0;
+    uint32_t length = mSelection.mAnchor ? 2 : 1;
+    if (NS_WARN_IF(!QueryCharRectArray(aWidget, startOffset, length, rects))) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p CacheTextRects(), FAILED, "
+         "couldn't retrieve text rect array around the selection anchor (%u)",
+         this, mSelection.mAnchor));
+      MOZ_ASSERT(mSelection.mAnchorCharRects[ePrevCharRect].IsEmpty());
+      MOZ_ASSERT(mSelection.mAnchorCharRects[eNextCharRect].IsEmpty());
+    } else {
+      if (rects.Length() > 1) {
+        mSelection.mAnchorCharRects[ePrevCharRect] = rects[0];
+        mSelection.mAnchorCharRects[eNextCharRect] = rects[1];
+      } else if (rects.Length()) {
+        mSelection.mAnchorCharRects[eNextCharRect] = rects[0];
+        MOZ_ASSERT(mSelection.mAnchorCharRects[ePrevCharRect].IsEmpty());
+      }
+    }
+  }
+
+  if (mSelection.Collapsed()) {
+    mSelection.mFocusCharRects[0] = mSelection.mAnchorCharRects[0];
+    mSelection.mFocusCharRects[1] = mSelection.mAnchorCharRects[1];
+  } else if (mTextRectArray.InRange(mSelection.mFocus) &&
+             (!mSelection.mFocus ||
+              mTextRectArray.InRange(mSelection.mFocus - 1))) {
+    mSelection.mFocusCharRects[eNextCharRect] =
+      mTextRectArray.GetRect(mSelection.mFocus);
+    if (mSelection.mFocus) {
+      mSelection.mFocusCharRects[ePrevCharRect] =
+        mTextRectArray.GetRect(mSelection.mFocus - 1);
+    }
+  } else {
+    RectArray rects;
+    uint32_t startOffset = mSelection.mFocus ? mSelection.mFocus - 1 : 0;
+    uint32_t length = mSelection.mFocus ? 2 : 1;
+    if (NS_WARN_IF(!QueryCharRectArray(aWidget, startOffset, length, rects))) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p CacheTextRects(), FAILED, "
+         "couldn't retrieve text rect array around the selection focus (%u)",
+         this, mSelection.mFocus));
+      MOZ_ASSERT(mSelection.mFocusCharRects[ePrevCharRect].IsEmpty());
+      MOZ_ASSERT(mSelection.mFocusCharRects[eNextCharRect].IsEmpty());
+    } else {
+      if (rects.Length() > 1) {
+        mSelection.mFocusCharRects[ePrevCharRect] = rects[0];
+        mSelection.mFocusCharRects[eNextCharRect] = rects[1];
+      } else if (rects.Length()) {
+        mSelection.mFocusCharRects[eNextCharRect] = rects[0];
+        MOZ_ASSERT(mSelection.mFocusCharRects[ePrevCharRect].IsEmpty());
+      }
+    }
+  }
+
+  if (!mSelection.Collapsed()) {
+    nsEventStatus status = nsEventStatus_eIgnore;
+    WidgetQueryContentEvent textRect(true, eQueryTextRect, aWidget);
+    textRect.InitForQueryTextRect(mSelection.StartOffset(),
+                                  mSelection.Length());
+    aWidget->DispatchEvent(&textRect, status);
+    if (NS_WARN_IF(!textRect.mSucceeded)) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p CacheTextRects(), FAILED, "
+         "couldn't retrieve text rect of whole selected text", this));
+    } else {
+      mSelection.mRect = textRect.mReply.mRect;
+    }
+  }
+
+  if (!mSelection.mFocus) {
+    mFirstCharRect = mSelection.mFocusCharRects[eNextCharRect];
+  } else if (mSelection.mFocus == 1) {
+    mFirstCharRect = mSelection.mFocusCharRects[ePrevCharRect];
+  } else if (!mSelection.mAnchor) {
+    mFirstCharRect = mSelection.mAnchorCharRects[eNextCharRect];
+  } else if (mSelection.mAnchor == 1) {
+    mFirstCharRect = mSelection.mFocusCharRects[ePrevCharRect];
+  } else if (mTextRectArray.InRange(0)) {
+    mFirstCharRect = mTextRectArray.GetRect(0);
+  } else {
+    LayoutDeviceIntRect charRect;
+    if (NS_WARN_IF(!QueryCharRect(aWidget, 0, charRect))) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p CacheTextRects(), FAILED, "
+         "couldn't retrieve first char rect", this));
+    } else {
+      mFirstCharRect = charRect;
+    }
+  }
+
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p CacheTextRects(), Succeeded, "
+     "mText.Length()=%u, mTextRectArray={ mStart=%u, mRects.Length()=%u }, "
+     "mSelection={ mAnchor=%u, mAnchorCharRects[eNextCharRect]=%s, "
+     "mAnchorCharRects[ePrevCharRect]=%s, mFocus=%u, "
+     "mFocusCharRects[eNextCharRect]=%s, mFocusCharRects[ePrevCharRect]=%s, "
+     "mRect=%s }, mFirstCharRect=%s",
+     this, mText.Length(), mTextRectArray.mStart,
+     mTextRectArray.mRects.Length(), mSelection.mAnchor,
+     GetRectText(mSelection.mAnchorCharRects[eNextCharRect]).get(),
+     GetRectText(mSelection.mAnchorCharRects[ePrevCharRect]).get(),
+     mSelection.mFocus,
+     GetRectText(mSelection.mFocusCharRects[eNextCharRect]).get(),
+     GetRectText(mSelection.mFocusCharRects[ePrevCharRect]).get(),
+     GetRectText(mSelection.mRect).get(), GetRectText(mFirstCharRect).get()));
+  return true;
+}
+
+void
+ContentCacheInChild::SetSelection(nsIWidget* aWidget,
+                                  uint32_t aStartOffset,
+                                  uint32_t aLength,
+                                  bool aReversed,
+                                  const WritingMode& aWritingMode)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p SetSelection(aStartOffset=%u, "
+     "aLength=%u, aReversed=%s, aWritingMode=%s), mText.Length()=%u",
+     this, aStartOffset, aLength, GetBoolName(aReversed),
+     GetWritingModeName(aWritingMode).get(), mText.Length()));
+
+  if (!aReversed) {
+    mSelection.mAnchor = aStartOffset;
+    mSelection.mFocus = aStartOffset + aLength;
+  } else {
+    mSelection.mAnchor = aStartOffset + aLength;
+    mSelection.mFocus = aStartOffset;
+  }
+  mSelection.mWritingMode = aWritingMode;
+
+  if (NS_WARN_IF(!CacheCaret(aWidget))) {
+    return;
+  }
+  Unused << NS_WARN_IF(!CacheTextRects(aWidget));
+}
+
+/*****************************************************************************
+ * mozilla::ContentCacheInParent
+ *****************************************************************************/
+
+ContentCacheInParent::ContentCacheInParent()
+  : ContentCache()
+  , mCommitStringByRequest(nullptr)
+  , mPendingEventsNeedingAck(0)
+  , mCompositionStartInChild(UINT32_MAX)
+  , mPendingCompositionCount(0)
+  , mWidgetHasComposition(false)
+{
+}
+
+void
+ContentCacheInParent::AssignContent(const ContentCache& aOther,
+                                    nsIWidget* aWidget,
+                                    const IMENotification* aNotification)
+{
+  mText = aOther.mText;
+  mSelection = aOther.mSelection;
+  mFirstCharRect = aOther.mFirstCharRect;
+  mCaret = aOther.mCaret;
+  mTextRectArray = aOther.mTextRectArray;
+  mEditorRect = aOther.mEditorRect;
+
+  // Only when there is one composition, the TextComposition instance in this
+  // process is managing the composition in the remote process.  Therefore,
+  // we shouldn't update composition start offset of TextComposition with
+  // old composition which is still being handled by the child process.
+  if (mWidgetHasComposition && mPendingCompositionCount == 1) {
+    IMEStateManager::MaybeStartOffsetUpdatedInChild(aWidget, mCompositionStart);
+  }
+
+  // When the widget has composition, we should set mCompositionStart to
+  // *current* composition start offset.  Note that, in strictly speaking,
+  // widget should not use WidgetQueryContentEvent if there are some pending
+  // compositions (i.e., when mPendingCompositionCount is 2 or more).
+  mCompositionStartInChild = aOther.mCompositionStart;
+  if (mWidgetHasComposition) {
+    if (aOther.mCompositionStart != UINT32_MAX) {
+      mCompositionStart = aOther.mCompositionStart;
+    } else {
+      mCompositionStart = mSelection.StartOffset();
+      NS_WARNING_ASSERTION(mCompositionStart != UINT32_MAX,
+                           "mCompositionStart shouldn't be invalid offset when "
+                           "the widget has composition");
+    }
+  } else {
+    mCompositionStart = UINT32_MAX;
+  }
+
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p AssignContent(aNotification=%s), "
+     "Succeeded, mText.Length()=%u, mSelection={ mAnchor=%u, mFocus=%u, "
+     "mWritingMode=%s, mAnchorCharRects[eNextCharRect]=%s, "
+     "mAnchorCharRects[ePrevCharRect]=%s, mFocusCharRects[eNextCharRect]=%s, "
+     "mFocusCharRects[ePrevCharRect]=%s, mRect=%s }, "
+     "mFirstCharRect=%s, mCaret={ mOffset=%u, mRect=%s }, mTextRectArray={ "
+     "mStart=%u, mRects.Length()=%u }, mWidgetHasComposition=%s, "
+     "mPendingCompositionCount=%u, mCompositionStart=%u, mEditorRect=%s",
+     this, GetNotificationName(aNotification),
+     mText.Length(), mSelection.mAnchor, mSelection.mFocus,
+     GetWritingModeName(mSelection.mWritingMode).get(),
+     GetRectText(mSelection.mAnchorCharRects[eNextCharRect]).get(),
+     GetRectText(mSelection.mAnchorCharRects[ePrevCharRect]).get(),
+     GetRectText(mSelection.mFocusCharRects[eNextCharRect]).get(),
+     GetRectText(mSelection.mFocusCharRects[ePrevCharRect]).get(),
+     GetRectText(mSelection.mRect).get(), GetRectText(mFirstCharRect).get(),
+     mCaret.mOffset, GetRectText(mCaret.mRect).get(), mTextRectArray.mStart,
+     mTextRectArray.mRects.Length(), GetBoolName(mWidgetHasComposition),
+     mPendingCompositionCount, mCompositionStart,
+     GetRectText(mEditorRect).get()));
+}
+
+bool
+ContentCacheInParent::HandleQueryContentEvent(WidgetQueryContentEvent& aEvent,
+                                              nsIWidget* aWidget) const
+{
+  MOZ_ASSERT(aWidget);
+
+  aEvent.mSucceeded = false;
+  aEvent.mReply.mFocusedWidget = aWidget;
+
+  // ContentCache doesn't store offset of its start with XP linebreaks.
+  // So, we don't support to query contents relative to composition start
+  // offset with XP linebreaks.
+  if (NS_WARN_IF(!aEvent.mUseNativeLineBreak)) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p HandleQueryContentEvent(), FAILED due to query with XP linebreaks",
+       this));
+    return false;
+  }
+
+  if (NS_WARN_IF(!aEvent.mInput.IsValidOffset())) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p HandleQueryContentEvent(), FAILED due to invalid offset",
+       this));
+    return false;
+  }
+
+  if (NS_WARN_IF(!aEvent.mInput.IsValidEventMessage(aEvent.mMessage))) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Error,
+      ("0x%p HandleQueryContentEvent(), FAILED due to invalid event message",
+       this));
+    return false;
+  }
+
+  bool isRelativeToInsertionPoint = aEvent.mInput.mRelativeToInsertionPoint;
+  if (isRelativeToInsertionPoint) {
+    if (aWidget->PluginHasFocus()) {
+      if (NS_WARN_IF(!aEvent.mInput.MakeOffsetAbsolute(0))) {
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), FAILED due to "
+           "aEvent.mInput.MakeOffsetAbsolute(0) failure, aEvent={ mMessage=%s, "
+           "mInput={ mOffset=%d, mLength=%d } }",
+           this, ToChar(aEvent.mMessage), aEvent.mInput.mOffset,
+           aEvent.mInput.mLength));
+        return false;
+      }
+    } else if (mWidgetHasComposition) {
+      if (NS_WARN_IF(!aEvent.mInput.MakeOffsetAbsolute(mCompositionStart))) {
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), FAILED due to "
+           "aEvent.mInput.MakeOffsetAbsolute(mCompositionStart) failure, "
+           "mCompositionStart=%d, aEvent={ mMessage=%s, "
+           "mInput={ mOffset=%d, mLength=%d } }",
+           this, mCompositionStart, ToChar(aEvent.mMessage),
+           aEvent.mInput.mOffset, aEvent.mInput.mLength));
+        return false;
+      }
+    } else if (NS_WARN_IF(!mSelection.IsValid())) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p HandleQueryContentEvent(), FAILED due to mSelection is invalid",
+         this));
+      return false;
+    } else if (NS_WARN_IF(!aEvent.mInput.MakeOffsetAbsolute(
+                                           mSelection.StartOffset()))) {
+      MOZ_LOG(sContentCacheLog, LogLevel::Error,
+        ("0x%p HandleQueryContentEvent(), FAILED due to "
+         "aEvent.mInput.MakeOffsetAbsolute(mSelection.StartOffset()) "
+         "failure, mSelection={ StartOffset()=%d, Length()=%d }, "
+         "aEvent={ mMessage=%s, mInput={ mOffset=%d, mLength=%d } }",
+         this, mSelection.StartOffset(), mSelection.Length(),
+         ToChar(aEvent.mMessage), aEvent.mInput.mOffset,
+         aEvent.mInput.mLength));
+      return false;
+    }
+  }
+
+  switch (aEvent.mMessage) {
+    case eQuerySelectedText:
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent("
+         "aEvent={ mMessage=eQuerySelectedText }, aWidget=0x%p)",
+         this, aWidget));
+      if (aWidget->PluginHasFocus()) {
+        MOZ_LOG(sContentCacheLog, LogLevel::Info,
+          ("0x%p HandleQueryContentEvent(), "
+           "return emtpy selection becasue plugin has focus",
+           this));
+        aEvent.mSucceeded = true;
+        aEvent.mReply.mOffset = 0;
+        aEvent.mReply.mReversed = false;
+        aEvent.mReply.mHasSelection = false;
+        return true;
+      }
+      if (NS_WARN_IF(!IsSelectionValid())) {
+        // If content cache hasn't been initialized properly, make the query
+        // failed.
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), "
+           "FAILED because mSelection is not valid", this));
+        return true;
+      }
+      aEvent.mReply.mOffset = mSelection.StartOffset();
+      if (mSelection.Collapsed()) {
+        aEvent.mReply.mString.Truncate(0);
+      } else {
+        if (NS_WARN_IF(mSelection.EndOffset() > mText.Length())) {
+          MOZ_LOG(sContentCacheLog, LogLevel::Error,
+            ("0x%p HandleQueryContentEvent(), "
+             "FAILED because mSelection.EndOffset()=%u is larger than "
+             "mText.Length()=%u",
+             this, mSelection.EndOffset(), mText.Length()));
+          return false;
+        }
+        aEvent.mReply.mString =
+          Substring(mText, aEvent.mReply.mOffset, mSelection.Length());
+      }
+      aEvent.mReply.mReversed = mSelection.Reversed();
+      aEvent.mReply.mHasSelection = true;
+      aEvent.mReply.mWritingMode = mSelection.mWritingMode;
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent(), "
+         "Succeeded, aEvent={ mReply={ mOffset=%u, mString=\"%s\", "
+         "mReversed=%s, mHasSelection=%s, mWritingMode=%s } }",
+         this, aEvent.mReply.mOffset,
+         GetEscapedUTF8String(aEvent.mReply.mString).get(),
+         GetBoolName(aEvent.mReply.mReversed),
+         GetBoolName(aEvent.mReply.mHasSelection),
+         GetWritingModeName(aEvent.mReply.mWritingMode).get()));
+      break;
+    case eQueryTextContent: {
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent("
+         "aEvent={ mMessage=eQueryTextContent, mInput={ mOffset=%u, "
+         "mLength=%u } }, aWidget=0x%p), mText.Length()=%u",
+         this, aEvent.mInput.mOffset,
+         aEvent.mInput.mLength, aWidget, mText.Length()));
+      uint32_t inputOffset = aEvent.mInput.mOffset;
+      uint32_t inputEndOffset =
+        std::min(aEvent.mInput.EndOffset(), mText.Length());
+      if (NS_WARN_IF(inputEndOffset < inputOffset)) {
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), "
+           "FAILED because inputOffset=%u is larger than inputEndOffset=%u",
+           this, inputOffset, inputEndOffset));
+        return false;
+      }
+      aEvent.mReply.mOffset = inputOffset;
+      aEvent.mReply.mString =
+        Substring(mText, inputOffset, inputEndOffset - inputOffset);
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent(), "
+         "Succeeded, aEvent={ mReply={ mOffset=%u, mString.Length()=%u } }",
+         this, aEvent.mReply.mOffset, aEvent.mReply.mString.Length()));
+      break;
+    }
+    case eQueryTextRect:
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent("
+         "aEvent={ mMessage=eQueryTextRect, mInput={ mOffset=%u, "
+         "mLength=%u } }, aWidget=0x%p), mText.Length()=%u",
+         this, aEvent.mInput.mOffset, aEvent.mInput.mLength, aWidget,
+         mText.Length()));
+      if (NS_WARN_IF(!IsSelectionValid())) {
+        // If content cache hasn't been initialized properly, make the query
+        // failed.
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), "
+           "FAILED because mSelection is not valid", this));
+        return true;
+      }
+      // Note that if the query is relative to insertion point, the query was
+      // probably requested by native IME.  In such case, we should return
+      // non-empty rect since returning failure causes IME showing its window
+      // at odd position.
+      if (aEvent.mInput.mLength) {
+        if (NS_WARN_IF(!GetUnionTextRects(aEvent.mInput.mOffset,
+                                          aEvent.mInput.mLength,
+                                          isRelativeToInsertionPoint,
+                                          aEvent.mReply.mRect))) {
+          // XXX We don't have cache for this request.
+          MOZ_LOG(sContentCacheLog, LogLevel::Error,
+            ("0x%p HandleQueryContentEvent(), "
+             "FAILED to get union rect", this));
+          return false;
+        }
+      } else {
+        // If the length is 0, we should return caret rect instead.
+        if (NS_WARN_IF(!GetCaretRect(aEvent.mInput.mOffset,
+                                     isRelativeToInsertionPoint,
+                                     aEvent.mReply.mRect))) {
+          MOZ_LOG(sContentCacheLog, LogLevel::Error,
+            ("0x%p HandleQueryContentEvent(), "
+             "FAILED to get caret rect", this));
+          return false;
+        }
+      }
+      if (aEvent.mInput.mOffset < mText.Length()) {
+        aEvent.mReply.mString =
+          Substring(mText, aEvent.mInput.mOffset,
+                    mText.Length() >= aEvent.mInput.EndOffset() ?
+                      aEvent.mInput.mLength : UINT32_MAX);
+      } else {
+        aEvent.mReply.mString.Truncate(0);
+      }
+      aEvent.mReply.mOffset = aEvent.mInput.mOffset;
+      // XXX This may be wrong if storing range isn't in the selection range.
+      aEvent.mReply.mWritingMode = mSelection.mWritingMode;
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent(), "
+         "Succeeded, aEvent={ mReply={ mOffset=%u, mString=\"%s\", "
+         "mWritingMode=%s, mRect=%s } }",
+         this, aEvent.mReply.mOffset,
+         GetEscapedUTF8String(aEvent.mReply.mString).get(),
+         GetWritingModeName(aEvent.mReply.mWritingMode).get(),
+         GetRectText(aEvent.mReply.mRect).get()));
+      break;
+    case eQueryCaretRect:
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent("
+         "aEvent={ mMessage=eQueryCaretRect, mInput={ mOffset=%u } }, "
+         "aWidget=0x%p), mText.Length()=%u",
+         this, aEvent.mInput.mOffset, aWidget, mText.Length()));
+      if (NS_WARN_IF(!IsSelectionValid())) {
+        // If content cache hasn't been initialized properly, make the query
+        // failed.
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), "
+           "FAILED because mSelection is not valid", this));
+        return true;
+      }
+      // Note that if the query is relative to insertion point, the query was
+      // probably requested by native IME.  In such case, we should return
+      // non-empty rect since returning failure causes IME showing its window
+      // at odd position.
+      if (NS_WARN_IF(!GetCaretRect(aEvent.mInput.mOffset,
+                                   isRelativeToInsertionPoint,
+                                   aEvent.mReply.mRect))) {
+        MOZ_LOG(sContentCacheLog, LogLevel::Error,
+          ("0x%p HandleQueryContentEvent(), "
+           "FAILED to get caret rect", this));
+        return false;
+      }
+      aEvent.mReply.mOffset = aEvent.mInput.mOffset;
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent(), "
+         "Succeeded, aEvent={ mReply={ mOffset=%u, mRect=%s } }",
+         this, aEvent.mReply.mOffset, GetRectText(aEvent.mReply.mRect).get()));
+      break;
+    case eQueryEditorRect:
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent("
+         "aEvent={ mMessage=eQueryEditorRect }, aWidget=0x%p)",
+         this, aWidget));
+      aEvent.mReply.mRect = mEditorRect;
+      MOZ_LOG(sContentCacheLog, LogLevel::Info,
+        ("0x%p HandleQueryContentEvent(), "
+         "Succeeded, aEvent={ mReply={ mRect=%s } }",
+         this, GetRectText(aEvent.mReply.mRect).get()));
+      break;
+    default:
+      break;
+  }
+  aEvent.mSucceeded = true;
+  return true;
+}
+
+bool
+ContentCacheInParent::GetTextRect(uint32_t aOffset,
+                                  bool aRoundToExistingOffset,
+                                  LayoutDeviceIntRect& aTextRect) const
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p GetTextRect(aOffset=%u, "
+     "aRoundToExistingOffset=%s), "
+     "mTextRectArray={ mStart=%u, mRects.Length()=%u }, "
+     "mSelection={ mAnchor=%u, mFocus=%u }",
+     this, aOffset, GetBoolName(aRoundToExistingOffset),
+     mTextRectArray.mStart, mTextRectArray.mRects.Length(),
+     mSelection.mAnchor, mSelection.mFocus));
+
+  if (!aOffset) {
+    NS_WARNING_ASSERTION(!mFirstCharRect.IsEmpty(), "empty rect");
+    aTextRect = mFirstCharRect;
+    return !aTextRect.IsEmpty();
+  }
+  if (aOffset == mSelection.mAnchor) {
+    NS_WARNING_ASSERTION(!mSelection.mAnchorCharRects[eNextCharRect].IsEmpty(),
+                         "empty rect");
+    aTextRect = mSelection.mAnchorCharRects[eNextCharRect];
+    return !aTextRect.IsEmpty();
+  }
+  if (mSelection.mAnchor && aOffset == mSelection.mAnchor - 1) {
+    NS_WARNING_ASSERTION(!mSelection.mAnchorCharRects[ePrevCharRect].IsEmpty(),
+                         "empty rect");
+    aTextRect = mSelection.mAnchorCharRects[ePrevCharRect];
+    return !aTextRect.IsEmpty();
+  }
+  if (aOffset == mSelection.mFocus) {
+    NS_WARNING_ASSERTION(!mSelection.mFocusCharRects[eNextCharRect].IsEmpty(),
+                         "empty rect");
+    aTextRect = mSelection.mFocusCharRects[eNextCharRect];
+    return !aTextRect.IsEmpty();
+  }
+  if (mSelection.mFocus && aOffset == mSelection.mFocus - 1) {
+    NS_WARNING_ASSERTION(!mSelection.mFocusCharRects[ePrevCharRect].IsEmpty(),
+                         "empty rect");
+    aTextRect = mSelection.mFocusCharRects[ePrevCharRect];
+    return !aTextRect.IsEmpty();
+  }
+
+  uint32_t offset = aOffset;
+  if (!mTextRectArray.InRange(aOffset)) {
+    if (!aRoundToExistingOffset) {
+      aTextRect.SetEmpty();
+      return false;
+    }
+    if (!mTextRectArray.IsValid()) {
+      // If there are no rects in mTextRectArray, we should refer the start of
+      // the selection because IME must query a char rect around it if there is
+      // no composition.
+      aTextRect = mSelection.StartCharRect();
+      return !aTextRect.IsEmpty();
+    }
+    if (offset < mTextRectArray.StartOffset()) {
+      offset = mTextRectArray.StartOffset();
+    } else {
+      offset = mTextRectArray.EndOffset() - 1;
+    }
+  }
+  aTextRect = mTextRectArray.GetRect(offset);
+  return !aTextRect.IsEmpty();
+}
+
+bool
+ContentCacheInParent::GetUnionTextRects(
+                        uint32_t aOffset,
+                        uint32_t aLength,
+                        bool aRoundToExistingOffset,
+                        LayoutDeviceIntRect& aUnionTextRect) const
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p GetUnionTextRects(aOffset=%u, "
+     "aLength=%u, aRoundToExistingOffset=%s), mTextRectArray={ "
+     "mStart=%u, mRects.Length()=%u }, "
+     "mSelection={ mAnchor=%u, mFocus=%u }",
+     this, aOffset, aLength, GetBoolName(aRoundToExistingOffset),
+     mTextRectArray.mStart, mTextRectArray.mRects.Length(),
+     mSelection.mAnchor, mSelection.mFocus));
+
+  CheckedInt<uint32_t> endOffset =
+    CheckedInt<uint32_t>(aOffset) + aLength;
+  if (!endOffset.isValid()) {
+    return false;
+  }
+
+  if (!mSelection.Collapsed() &&
+      aOffset == mSelection.StartOffset() && aLength == mSelection.Length()) {
+    NS_WARNING_ASSERTION(!mSelection.mRect.IsEmpty(), "empty rect");
+    aUnionTextRect = mSelection.mRect;
+    return !aUnionTextRect.IsEmpty();
+  }
+
+  if (aLength == 1) {
+    if (!aOffset) {
+      NS_WARNING_ASSERTION(!mFirstCharRect.IsEmpty(), "empty rect");
+      aUnionTextRect = mFirstCharRect;
+      return !aUnionTextRect.IsEmpty();
+    }
+    if (aOffset == mSelection.mAnchor) {
+      NS_WARNING_ASSERTION(
+        !mSelection.mAnchorCharRects[eNextCharRect].IsEmpty(), "empty rect");
+      aUnionTextRect = mSelection.mAnchorCharRects[eNextCharRect];
+      return !aUnionTextRect.IsEmpty();
+    }
+    if (mSelection.mAnchor && aOffset == mSelection.mAnchor - 1) {
+      NS_WARNING_ASSERTION(
+        !mSelection.mAnchorCharRects[ePrevCharRect].IsEmpty(), "empty rect");
+      aUnionTextRect = mSelection.mAnchorCharRects[ePrevCharRect];
+      return !aUnionTextRect.IsEmpty();
+    }
+    if (aOffset == mSelection.mFocus) {
+      NS_WARNING_ASSERTION(
+        !mSelection.mFocusCharRects[eNextCharRect].IsEmpty(), "empty rect");
+      aUnionTextRect = mSelection.mFocusCharRects[eNextCharRect];
+      return !aUnionTextRect.IsEmpty();
+    }
+    if (mSelection.mFocus && aOffset == mSelection.mFocus - 1) {
+      NS_WARNING_ASSERTION(
+        !mSelection.mFocusCharRects[ePrevCharRect].IsEmpty(), "empty rect");
+      aUnionTextRect = mSelection.mFocusCharRects[ePrevCharRect];
+      return !aUnionTextRect.IsEmpty();
+    }
+  }
+
+  // Even if some text rects are not cached of the queried range,
+  // we should return union rect when the first character's rect is cached
+  // since the first character rect is important and the others are not so
+  // in most cases.
+
+  if (!aOffset && aOffset != mSelection.mAnchor &&
+      aOffset != mSelection.mFocus && !mTextRectArray.InRange(aOffset)) {
+    // The first character rect isn't cached.
+    return false;
+  }
+
+  if ((aRoundToExistingOffset && mTextRectArray.HasRects()) ||
+      mTextRectArray.IsOverlappingWith(aOffset, aLength)) {
+    aUnionTextRect =
+      mTextRectArray.GetUnionRectAsFarAsPossible(aOffset, aLength,
+                                                 aRoundToExistingOffset);
+  } else {
+    aUnionTextRect.SetEmpty();
+  }
+
+  if (!aOffset) {
+    aUnionTextRect = aUnionTextRect.Union(mFirstCharRect);
+  }
+  if (aOffset <= mSelection.mAnchor && mSelection.mAnchor < endOffset.value()) {
+    aUnionTextRect =
+      aUnionTextRect.Union(mSelection.mAnchorCharRects[eNextCharRect]);
+  }
+  if (mSelection.mAnchor && aOffset <= mSelection.mAnchor - 1 &&
+      mSelection.mAnchor - 1 < endOffset.value()) {
+    aUnionTextRect =
+      aUnionTextRect.Union(mSelection.mAnchorCharRects[ePrevCharRect]);
+  }
+  if (aOffset <= mSelection.mFocus && mSelection.mFocus < endOffset.value()) {
+    aUnionTextRect =
+      aUnionTextRect.Union(mSelection.mFocusCharRects[eNextCharRect]);
+  }
+  if (mSelection.mFocus && aOffset <= mSelection.mFocus - 1 &&
+      mSelection.mFocus - 1 < endOffset.value()) {
+    aUnionTextRect =
+      aUnionTextRect.Union(mSelection.mFocusCharRects[ePrevCharRect]);
+  }
+
+  return !aUnionTextRect.IsEmpty();
+}
+
+bool
+ContentCacheInParent::GetCaretRect(uint32_t aOffset,
+                                   bool aRoundToExistingOffset,
+                                   LayoutDeviceIntRect& aCaretRect) const
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p GetCaretRect(aOffset=%u, "
+     "aRoundToExistingOffset=%s), "
+     "mCaret={ mOffset=%u, mRect=%s, IsValid()=%s }, mTextRectArray={ "
+     "mStart=%u, mRects.Length()=%u }, mSelection={ mAnchor=%u, mFocus=%u, "
+     "mWritingMode=%s, mAnchorCharRects[eNextCharRect]=%s, "
+     "mAnchorCharRects[ePrevCharRect]=%s, mFocusCharRects[eNextCharRect]=%s, "
+     "mFocusCharRects[ePrevCharRect]=%s }, mFirstCharRect=%s",
+     this, aOffset, GetBoolName(aRoundToExistingOffset),
+     mCaret.mOffset, GetRectText(mCaret.mRect).get(),
+     GetBoolName(mCaret.IsValid()), mTextRectArray.mStart,
+     mTextRectArray.mRects.Length(), mSelection.mAnchor, mSelection.mFocus,
+     GetWritingModeName(mSelection.mWritingMode).get(),
+     GetRectText(mSelection.mAnchorCharRects[eNextCharRect]).get(),
+     GetRectText(mSelection.mAnchorCharRects[ePrevCharRect]).get(),
+     GetRectText(mSelection.mFocusCharRects[eNextCharRect]).get(),
+     GetRectText(mSelection.mFocusCharRects[ePrevCharRect]).get(),
+     GetRectText(mFirstCharRect).get()));
+
+  if (mCaret.IsValid() && mCaret.mOffset == aOffset) {
+    aCaretRect = mCaret.mRect;
+    return true;
+  }
+
+  // Guess caret rect from the text rect if it's stored.
+  if (!GetTextRect(aOffset, aRoundToExistingOffset, aCaretRect)) {
+    // There might be previous character rect in the cache.  If so, we can
+    // guess the caret rect with it.
+    if (!aOffset ||
+        !GetTextRect(aOffset - 1, aRoundToExistingOffset, aCaretRect)) {
+      aCaretRect.SetEmpty();
+      return false;
+    }
+
+    if (mSelection.mWritingMode.IsVertical()) {
+      aCaretRect.y = aCaretRect.YMost();
+    } else {
+      // XXX bidi-unaware.
+      aCaretRect.x = aCaretRect.XMost();
+    }
+  }
+
+  // XXX This is not bidi aware because we don't cache each character's
+  //     direction.  However, this is usually used by IME, so, assuming the
+  //     character is in LRT context must not cause any problem.
+  if (mSelection.mWritingMode.IsVertical()) {
+    aCaretRect.height = mCaret.IsValid() ? mCaret.mRect.height : 1;
+  } else {
+    aCaretRect.width = mCaret.IsValid() ? mCaret.mRect.width : 1;
+  }
+  return true;
+}
+
+bool
+ContentCacheInParent::OnCompositionEvent(const WidgetCompositionEvent& aEvent)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p OnCompositionEvent(aEvent={ "
+     "mMessage=%s, mData=\"%s\" (Length()=%u), mRanges->Length()=%u }), "
+     "mPendingEventsNeedingAck=%u, mWidgetHasComposition=%s, "
+     "mPendingCompositionCount=%u, mCommitStringByRequest=0x%p",
+     this, ToChar(aEvent.mMessage),
+     GetEscapedUTF8String(aEvent.mData).get(), aEvent.mData.Length(),
+     aEvent.mRanges ? aEvent.mRanges->Length() : 0, mPendingEventsNeedingAck,
+     GetBoolName(mWidgetHasComposition), mPendingCompositionCount,
+     mCommitStringByRequest));
+
+  // We must be able to simulate the selection because
+  // we might not receive selection updates in time
+  if (!mWidgetHasComposition) {
+    if (aEvent.mWidget && aEvent.mWidget->PluginHasFocus()) {
+      // If focus is on plugin, we cannot get selection range
+      mCompositionStart = 0;
+    } else if (mCompositionStartInChild != UINT32_MAX) {
+      // If there is pending composition in the remote process, let's use
+      // its start offset temporarily because this stores a lot of information
+      // around it and the user must look around there, so, showing some UI
+      // around it must make sense.
+      mCompositionStart = mCompositionStartInChild;
+    } else {
+      mCompositionStart = mSelection.StartOffset();
+    }
+    MOZ_ASSERT(aEvent.mMessage == eCompositionStart);
+    MOZ_RELEASE_ASSERT(mPendingCompositionCount < UINT8_MAX);
+    mPendingCompositionCount++;
+  }
+
+  mWidgetHasComposition = !aEvent.CausesDOMCompositionEndEvent();
+
+  if (!mWidgetHasComposition) {
+    mCompositionStart = UINT32_MAX;
+  }
+
+  // During REQUEST_TO_COMMIT_COMPOSITION or REQUEST_TO_CANCEL_COMPOSITION,
+  // widget usually sends a eCompositionChange and/or eCompositionCommit event
+  // to finalize or clear the composition, respectively.  In this time,
+  // we need to intercept all composition events here and pass the commit
+  // string for returning to the remote process as a result of
+  // RequestIMEToCommitComposition().  Then, eCommitComposition event will
+  // be dispatched with the committed string in the remote process internally.
+  if (mCommitStringByRequest) {
+    MOZ_ASSERT(aEvent.mMessage == eCompositionChange ||
+               aEvent.mMessage == eCompositionCommit);
+    *mCommitStringByRequest = aEvent.mData;
+    return false;
+  }
+
+  mPendingEventsNeedingAck++;
+  return true;
+}
+
+void
+ContentCacheInParent::OnSelectionEvent(
+                        const WidgetSelectionEvent& aSelectionEvent)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p OnSelectionEvent(aEvent={ "
+     "mMessage=%s, mOffset=%u, mLength=%u, mReversed=%s, "
+     "mExpandToClusterBoundary=%s, mUseNativeLineBreak=%s }), "
+     "mPendingEventsNeedingAck=%u, mWidgetHasComposition=%s, "
+     "mPendingCompositionCount=%u",
+     this, ToChar(aSelectionEvent.mMessage),
+     aSelectionEvent.mOffset, aSelectionEvent.mLength,
+     GetBoolName(aSelectionEvent.mReversed),
+     GetBoolName(aSelectionEvent.mExpandToClusterBoundary),
+     GetBoolName(aSelectionEvent.mUseNativeLineBreak), mPendingEventsNeedingAck,
+     GetBoolName(mWidgetHasComposition), mPendingCompositionCount));
+
+  mPendingEventsNeedingAck++;
+}
+
+void
+ContentCacheInParent::OnEventNeedingAckHandled(nsIWidget* aWidget,
+                                                EventMessage aMessage)
+{
+  // This is called when the child process receives WidgetCompositionEvent or
+  // WidgetSelectionEvent.
+
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p OnEventNeedingAckHandled(aWidget=0x%p, "
+     "aMessage=%s), mPendingEventsNeedingAck=%u, mPendingCompositionCount=%u",
+     this, aWidget, ToChar(aMessage), mPendingEventsNeedingAck));
+
+  if (WidgetCompositionEvent::IsFollowedByCompositionEnd(aMessage)) {
+    MOZ_RELEASE_ASSERT(mPendingCompositionCount > 0);
+    mPendingCompositionCount--;
+  }
+
+  MOZ_RELEASE_ASSERT(mPendingEventsNeedingAck > 0);
+  if (--mPendingEventsNeedingAck) {
+    return;
+  }
+
+  FlushPendingNotifications(aWidget);
+}
+
+bool
+ContentCacheInParent::RequestIMEToCommitComposition(nsIWidget* aWidget,
+                                                    bool aCancel,
+                                                    nsAString& aCommittedString)
+{
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("0x%p RequestToCommitComposition(aWidget=%p, "
+     "aCancel=%s), mWidgetHasComposition=%s, mCommitStringByRequest=%p",
+     this, aWidget, GetBoolName(aCancel), GetBoolName(mWidgetHasComposition),
+     mCommitStringByRequest));
+
+  MOZ_ASSERT(!mCommitStringByRequest);
+
+  RefPtr<TextComposition> composition =
+    IMEStateManager::GetTextCompositionFor(aWidget);
+  if (NS_WARN_IF(!composition)) {
+    MOZ_LOG(sContentCacheLog, LogLevel::Warning,
+      ("  0x%p RequestToCommitComposition(), "
+       "does nothing due to no composition", this));
+    return false;
+  }
+
+  mCommitStringByRequest = &aCommittedString;
+
+  aWidget->NotifyIME(IMENotification(aCancel ? REQUEST_TO_CANCEL_COMPOSITION :
+                                               REQUEST_TO_COMMIT_COMPOSITION));
+
+  mCommitStringByRequest = nullptr;
+
+  MOZ_LOG(sContentCacheLog, LogLevel::Info,
+    ("  0x%p RequestToCommitComposition(), "
+     "mWidgetHasComposition=%s, the composition %s committed synchronously",
+     this, GetBoolName(mWidgetHasComposition),
+     composition->Destroyed() ? "WAS" : "has NOT been"));
+
+  if (!composition->Destroyed()) {
+    // When the composition isn't committed synchronously, the remote process's
+    // TextComposition instance will synthesize commit events and wait to
+    // receive delayed composition events.  When TextComposition instances both
+    // in this process and the remote process will be destroyed when delayed
+    // composition events received. TextComposition instance in the parent
+    // process will dispatch following composition events and be destroyed
+    // normally. On the other hand, TextComposition instance in the remote
+    // process won't dispatch following composition events and will be
+    // destroyed by IMEStateManager::DispatchCompositionEvent().
+    return false;
+  }
+
+  // When the composition is committed synchronously, the commit string will be
+  // returned to the remote process. Then, PuppetWidget will dispatch
+  // eCompositionCommit event with the returned commit string (i.e., the value
+  // is aCommittedString of this method).  Finally, TextComposition instance in
+  // the remote process will be destroyed by
+  // IMEStateManager::DispatchCompositionEvent() at receiving the
+  // eCompositionCommit event (Note that TextComposition instance in this
+  // process was already destroyed).
+  return true;
+}
+
+void
+ContentCacheInParent::MaybeNotifyIME(nsIWidget* aWidget,
+                                     const IMENotification& aNotification)
+{
+  if (!mPendingEventsNeedingAck) {
+    IMEStateManager::NotifyIME(aNotification, aWidget, true);
+    return;
+  }
+
+  switch (aNotification.mMessage) {
+    case NOTIFY_IME_OF_SELECTION_CHANGE:
+      mPendingSelectionChange.MergeWith(aNotification);
+      break;
+    case NOTIFY_IME_OF_TEXT_CHANGE:
+      mPendingTextChange.MergeWith(aNotification);
+      break;
+    case NOTIFY_IME_OF_POSITION_CHANGE:
+      mPendingLayoutChange.MergeWith(aNotification);
+      break;
+    case NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED:
+      mPendingCompositionUpdate.MergeWith(aNotification);
+      break;
+    default:
+      MOZ_CRASH("Unsupported notification");
+      break;
+  }
+}
+
+void
+ContentCacheInParent::FlushPendingNotifications(nsIWidget* aWidget)
+{
+  MOZ_ASSERT(!mPendingEventsNeedingAck);
+
+  // New notifications which are notified during flushing pending notifications
+  // should be merged again.
+  mPendingEventsNeedingAck++;
+
+  nsCOMPtr<nsIWidget> kungFuDeathGrip(aWidget);
+
+  // First, text change notification should be sent because selection change
+  // notification notifies IME of current selection range in the latest content.
+  // So, IME may need the latest content before that.
+  if (mPendingTextChange.HasNotification()) {
+    IMENotification notification(mPendingTextChange);
+    if (!aWidget->Destroyed()) {
+      mPendingTextChange.Clear();
+      IMEStateManager::NotifyIME(notification, aWidget, true);
+    }
+  }
+
+  if (mPendingSelectionChange.HasNotification()) {
+    IMENotification notification(mPendingSelectionChange);
+    if (!aWidget->Destroyed()) {
+      mPendingSelectionChange.Clear();
+      IMEStateManager::NotifyIME(notification, aWidget, true);
+    }
+  }
+
+  // Layout change notification should be notified after selection change
+  // notification because IME may want to query position of new caret position.
+  if (mPendingLayoutChange.HasNotification()) {
+    IMENotification notification(mPendingLayoutChange);
+    if (!aWidget->Destroyed()) {
+      mPendingLayoutChange.Clear();
+      IMEStateManager::NotifyIME(notification, aWidget, true);
+    }
+  }
+
+  // Finally, send composition update notification because it notifies IME of
+  // finishing handling whole sending events.
+  if (mPendingCompositionUpdate.HasNotification()) {
+    IMENotification notification(mPendingCompositionUpdate);
+    if (!aWidget->Destroyed()) {
+      mPendingCompositionUpdate.Clear();
+      IMEStateManager::NotifyIME(notification, aWidget, true);
+    }
+  }
+
+  if (!--mPendingEventsNeedingAck && !aWidget->Destroyed() &&
+      (mPendingTextChange.HasNotification() ||
+       mPendingSelectionChange.HasNotification() ||
+       mPendingLayoutChange.HasNotification() ||
+       mPendingCompositionUpdate.HasNotification())) {
+    FlushPendingNotifications(aWidget);
+  }
+}
+
+/*****************************************************************************
+ * mozilla::ContentCache::TextRectArray
+ *****************************************************************************/
+
+LayoutDeviceIntRect
+ContentCache::TextRectArray::GetRect(uint32_t aOffset) const
+{
+  LayoutDeviceIntRect rect;
+  if (InRange(aOffset)) {
+    rect = mRects[aOffset - mStart];
+  }
+  return rect;
+}
+
+LayoutDeviceIntRect
+ContentCache::TextRectArray::GetUnionRect(uint32_t aOffset,
+                                          uint32_t aLength) const
+{
+  LayoutDeviceIntRect rect;
+  if (!InRange(aOffset, aLength)) {
+    return rect;
+  }
+  for (uint32_t i = 0; i < aLength; i++) {
+    rect = rect.Union(mRects[aOffset - mStart + i]);
+  }
+  return rect;
+}
+
+LayoutDeviceIntRect
+ContentCache::TextRectArray::GetUnionRectAsFarAsPossible(
+                               uint32_t aOffset,
+                               uint32_t aLength,
+                               bool aRoundToExistingOffset) const
+{
+  LayoutDeviceIntRect rect;
+  if (!HasRects() ||
+      (!aRoundToExistingOffset && !IsOverlappingWith(aOffset, aLength))) {
+    return rect;
+  }
+  uint32_t startOffset = std::max(aOffset, mStart);
+  if (aRoundToExistingOffset && startOffset >= EndOffset()) {
+    startOffset = EndOffset() - 1;
+  }
+  uint32_t endOffset = std::min(aOffset + aLength, EndOffset());
+  if (aRoundToExistingOffset && endOffset < mStart + 1) {
+    endOffset = mStart + 1;
+  }
+  if (NS_WARN_IF(endOffset < startOffset)) {
+    return rect;
+  }
+  for (uint32_t i = 0; i < endOffset - startOffset; i++) {
+    rect = rect.Union(mRects[startOffset - mStart + i]);
+  }
+  return rect;
+}
+
+} // namespace mozilla