Bug 1296516 - Cleanup a bit of code in layout/base

* Tidy RestyleManager::ContentStateChanged
* Convert UndisplayedMap to a typed hashtable
* Cleanup infallible or unchecked nsCSSFrameConstructor methods

Tag mcp-graveyard/UXP#1375

13 files changed, 358 insertions, 459 deletions

diff --git a/layout/base/RestyleManager.cpp b/layout/base/RestyleManager.cpp
index 16db4c18b9..4d08dee067 100644
--- a/layout/base/RestyleManager.cpp
+++ b/layout/base/RestyleManager.cpp
@@ -246,14 +246,14 @@ ElementForStyleContext(nsIContent* aParentContent,
 
 // Forwarded nsIDocumentObserver method, to handle restyling (and
 // passing the notification to the frame).
-nsresult
+void
 RestyleManager::ContentStateChanged(nsIContent* aContent,
                                     EventStates aStateMask)
 {
   // XXXbz it would be good if this function only took Elements, but
   // we'd have to make ESM guarantee that usefully.
   if (!aContent->IsElement()) {
-    return NS_OK;
+    return;
   }
 
   Element* aElement = aContent->AsElement();
@@ -263,7 +263,6 @@ RestyleManager::ContentStateChanged(nsIContent* aContent,
   ContentStateChangedInternal(aElement, aStateMask, &changeHint, &restyleHint);
 
   PostRestyleEvent(aElement, restyleHint, changeHint);
-  return NS_OK;
 }
 
 // Forwarded nsIMutationObserver method, to handle restyling.
@@ -1830,7 +1829,7 @@ ElementRestyler::ConditionallyRestyleUndisplayedNodes(
   }
 
   for (UndisplayedNode* undisplayed = aUndisplayed; undisplayed;
-       undisplayed = undisplayed->mNext) {
+       undisplayed = undisplayed->getNext()) {
 
     if (!undisplayed->mContent->IsElement()) {
       continue;
@@ -3471,7 +3470,7 @@ ElementRestyler::RestyleUndisplayedNodes(nsRestyleHint      aChildRestyleHint,
   if (undisplayed) {
     pusher.PushAncestorAndStyleScope(undisplayedParent);
   }
-  for (; undisplayed; undisplayed = undisplayed->mNext) {
+  for (; undisplayed; undisplayed = undisplayed->getNext()) {
     NS_ASSERTION(undisplayedParent ||
                  undisplayed->mContent ==
                    mPresContext->Document()->GetRootElement(),
diff --git a/layout/base/RestyleManager.h b/layout/base/RestyleManager.h
index e22fe90581..3b60b331a6 100644
--- a/layout/base/RestyleManager.h
+++ b/layout/base/RestyleManager.h
@@ -59,8 +59,8 @@ public:
 
   // Forwarded nsIDocumentObserver method, to handle restyling (and
   // passing the notification to the frame).
-  nsresult ContentStateChanged(nsIContent*   aContent,
-                               EventStates aStateMask);
+  void ContentStateChanged(nsIContent* aContent,
+                           EventStates aStateMask);
 
   // Forwarded nsIMutationObserver method, to handle restyling.
   void AttributeWillChange(Element* aElement,
diff --git a/layout/base/RestyleManagerHandle.h b/layout/base/RestyleManagerHandle.h
index 8be04d12c1..bee1fc6d9e 100644
--- a/layout/base/RestyleManagerHandle.h
+++ b/layout/base/RestyleManagerHandle.h
@@ -125,8 +125,8 @@ public:
                                          nsIContent* aChild);
     inline void RestyleForAppend(nsIContent* aContainer,
                                  nsIContent* aFirstNewContent);
-    inline nsresult ContentStateChanged(nsIContent* aContent,
-                                        EventStates aStateMask);
+  inline void ContentStateChanged(nsIContent* aContent,
+                                  EventStates aStateMask);
     inline void AttributeWillChange(dom::Element* aElement,
                                     int32_t aNameSpaceID,
                                     nsIAtom* aAttribute,
diff --git a/layout/base/RestyleManagerHandleInlines.h b/layout/base/RestyleManagerHandleInlines.h
index cc374edd52..8d6ca9142b 100644
--- a/layout/base/RestyleManagerHandleInlines.h
+++ b/layout/base/RestyleManagerHandleInlines.h
@@ -122,7 +122,7 @@ RestyleManagerHandle::Ptr::RestyleForAppend(nsIContent* aContainer,
   FORWARD(RestyleForAppend, (aContainer, aFirstNewContent));
 }
 
-nsresult
+void
 RestyleManagerHandle::Ptr::ContentStateChanged(nsIContent* aContent,
                                           EventStates aStateMask)
 {
diff --git a/layout/base/ServoRestyleManager.cpp b/layout/base/ServoRestyleManager.cpp
index 42ca23bb10..9624c678be 100644
--- a/layout/base/ServoRestyleManager.cpp
+++ b/layout/base/ServoRestyleManager.cpp
@@ -513,12 +513,12 @@ ServoRestyleManager::ContentRemoved(nsINode* aContainer,
   NS_WARNING("stylo: ServoRestyleManager::ContentRemoved not implemented");
 }
 
-nsresult
+void
 ServoRestyleManager::ContentStateChanged(nsIContent* aContent,
                                          EventStates aChangedBits)
 {
   if (!aContent->IsElement()) {
-    return NS_OK;
+    return;
   }
 
   Element* aElement = aContent->AsElement();
@@ -552,7 +552,6 @@ ServoRestyleManager::ContentStateChanged(nsIContent* aContent,
   snapshot->AddState(previousState);
 
   PostRestyleEvent(aElement, restyleHint, changeHint);
-  return NS_OK;
 }
 
 void
diff --git a/layout/base/ServoRestyleManager.h b/layout/base/ServoRestyleManager.h
index 6856171c18..b6bb63d085 100644
--- a/layout/base/ServoRestyleManager.h
+++ b/layout/base/ServoRestyleManager.h
@@ -63,8 +63,7 @@ public:
                                 nsIContent* aChild);
   void RestyleForAppend(nsIContent* aContainer,
                         nsIContent* aFirstNewContent);
-  nsresult ContentStateChanged(nsIContent* aContent,
-                               EventStates aStateMask);
+  void ContentStateChanged(nsIContent* aContent, EventStates aStateMask);
   void AttributeWillChange(dom::Element* aElement,
                            int32_t aNameSpaceID,
                            nsIAtom* aAttribute,
diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
index b574e7690c..b9778d36de 100644
--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -3189,7 +3189,7 @@ nsCSSFrameConstructor::ConstructSelectFrame(nsFrameConstructorState& aState,
  * But the select tag should really be fixed to use GFX scrollbars that can
  * be create with BuildScrollFrame.
  */
-nsresult
+void
 nsCSSFrameConstructor::InitializeSelectFrame(nsFrameConstructorState& aState,
                                              nsContainerFrame*        scrollFrame,
                                              nsContainerFrame*        scrolledFrame,
@@ -3235,7 +3235,6 @@ nsCSSFrameConstructor::InitializeSelectFrame(nsFrameConstructorState& aState,
 
   // Set the scrolled frame's initial child lists
   scrolledFrame->SetInitialChildList(kPrincipalList, childItems);
-  return NS_OK;
 }
 
 nsIFrame*
@@ -6210,16 +6209,16 @@ IsRootBoxFrame(nsIFrame *aFrame)
   return (aFrame->GetType() == nsGkAtoms::rootFrame);
 }
 
-nsresult
+void
 nsCSSFrameConstructor::ReconstructDocElementHierarchy()
 {
   Element* rootElement = mDocument->GetRootElement();
   if (!rootElement) {
     /* nothing to do */
-    return NS_OK;
+    return;
   }
-  return RecreateFramesForContent(rootElement, false, REMOVE_FOR_RECONSTRUCTION,
-                                  nullptr);
+  RecreateFramesForContent(rootElement, false, REMOVE_FOR_RECONSTRUCTION,
+                           nullptr);
 }
 
 nsContainerFrame*
@@ -6469,7 +6468,7 @@ GetInsertNextSibling(nsIFrame* aParentFrame, nsIFrame* aPrevSibling)
  * appending flowed frames to a parent's principal child list. It handles the
  * case where the parent is the trailing inline of an {ib} split.
  */
-nsresult
+void
 nsCSSFrameConstructor::AppendFramesToParent(nsFrameConstructorState&       aState,
                                             nsContainerFrame*              aParentFrame,
                                             nsFrameItems&                  aFrameList,
@@ -6554,13 +6553,11 @@ nsCSSFrameConstructor::AppendFramesToParent(nsFrameConstructorState&       aStat
       return AppendFramesToParent(aState, aParentFrame->GetParent(), ibSiblings,
                                   aParentFrame, true);
     }
-
-    return NS_OK;
+    return;
   }
 
   // Insert the frames after our aPrevSibling
   InsertFrames(aParentFrame, kPrincipalList, aPrevSibling, aFrameList);
-  return NS_OK;
 }
 
 #define UNSET_DISPLAY static_cast<StyleDisplay>(255)
@@ -7308,7 +7305,7 @@ nsCSSFrameConstructor::MaybeRecreateForFrameset(nsIFrame* aParentFrame,
   return false;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
                                        nsIContent*     aFirstNewContent,
                                        bool            aAllowLazyConstruction)
@@ -7351,8 +7348,8 @@ nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
     if (tag == nsGkAtoms::treechildren ||
         tag == nsGkAtoms::treeitem ||
         tag == nsGkAtoms::treerow)
-      return NS_OK;
 
+      return;
   }
 #endif // MOZ_XUL
 
@@ -7365,21 +7362,21 @@ nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
     //XXXsmaug This is super unefficient!
     nsIContent* bindingParent = aContainer->GetBindingParent();
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(bindingParent, false,
-                                           REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(bindingParent, false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   // See comment in ContentRangeInserted for why this is necessary.
   if (!GetContentInsertionFrameFor(aContainer) &&
       !aContainer->IsActiveChildrenElement()) {
-    return NS_OK;
+    return;
   }
 
   if (aAllowLazyConstruction &&
       MaybeConstructLazily(CONTENTAPPEND, aContainer, aFirstNewContent)) {
-    return NS_OK;
+    return;
   }
 
   LAYOUT_PHASE_TEMP_EXIT();
@@ -7389,13 +7386,13 @@ nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
   nsContainerFrame*& parentFrame = insertion.mParentFrame;
   LAYOUT_PHASE_TEMP_REENTER();
   if (!parentFrame) {
-    return NS_OK;
+    return;
   }
 
   LAYOUT_PHASE_TEMP_EXIT();
   if (MaybeRecreateForFrameset(parentFrame, aFirstNewContent, nullptr)) {
     LAYOUT_PHASE_TEMP_REENTER();
-    return NS_OK;
+    return;
   }
   LAYOUT_PHASE_TEMP_REENTER();
 
@@ -7403,15 +7400,15 @@ nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
     // Nothing to do here; we shouldn't be constructing kids of leaves
     // Clear lazy bits so we don't try to construct again.
     ClearLazyBits(aFirstNewContent, nullptr);
-    return NS_OK;
+    return;
   }
 
   if (parentFrame->IsFrameOfType(nsIFrame::eMathML)) {
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(parentFrame->GetContent(), false,
-                                           REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(parentFrame->GetContent(), false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   // If the frame we are manipulating is a ib-split frame (that is, one
@@ -7509,7 +7506,7 @@ nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
   if (WipeContainingBlock(state, containingBlock, parentFrame, items,
                           true, prevSibling)) {
     LAYOUT_PHASE_TEMP_REENTER();
-    return NS_OK;
+    return;
   }
   LAYOUT_PHASE_TEMP_REENTER();
 
@@ -7596,7 +7593,7 @@ nsCSSFrameConstructor::ContentAppended(nsIContent*     aContainer,
   }
 #endif
 
-  return NS_OK;
+  return;
 }
 
 #ifdef MOZ_XUL
@@ -7639,17 +7636,17 @@ bool NotifyListBoxBody(nsPresContext*    aPresContext,
 }
 #endif // MOZ_XUL
 
-nsresult
+void
 nsCSSFrameConstructor::ContentInserted(nsIContent*            aContainer,
                                        nsIContent*            aChild,
                                        nsILayoutHistoryState* aFrameState,
                                        bool                   aAllowLazyConstruction)
 {
-  return ContentRangeInserted(aContainer,
-                              aChild,
-                              aChild->GetNextSibling(),
-                              aFrameState,
-                              aAllowLazyConstruction);
+  ContentRangeInserted(aContainer,
+                       aChild,
+                       aChild->GetNextSibling(),
+                       aFrameState,
+                       aAllowLazyConstruction);
 }
 
 // ContentRangeInserted handles creating frames for a range of nodes that
@@ -7670,7 +7667,7 @@ nsCSSFrameConstructor::ContentInserted(nsIContent*            aContainer,
 // in the caption list, while skipping any nodes in the range being inserted
 // (because when we treat the caption frames the other nodes have had their
 // frames constructed but not yet inserted into the frame tree).
-nsresult
+void
 nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
                                             nsIContent*            aStartChild,
                                             nsIContent*            aEndChild,
@@ -7727,7 +7724,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
                             // The insert case in NotifyListBoxBody
                             // doesn't use "old next sibling".
                             aStartChild, nullptr, nullptr, CONTENT_INSERTED)) {
-        return NS_OK;
+        return;
       }
     } else {
       // We don't handle a range insert to a listbox parent, issue single
@@ -7736,7 +7733,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
       IssueSingleInsertNofications(aContainer, aStartChild, aEndChild,
                                    aAllowLazyConstruction);
       LAYOUT_PHASE_TEMP_REENTER();
-      return NS_OK;
+      return;
     }
   }
 #endif // MOZ_XUL
@@ -7751,7 +7748,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
 
     if (aStartChild != docElement) {
       // Not the root element; just bail out
-      return NS_OK;
+      return;
     }
 
     NS_PRECONDITION(nullptr == mRootElementFrame,
@@ -7788,7 +7785,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
     }
 #endif
 
-    return NS_OK;
+    return;
   }
 
   if (aContainer->HasFlag(NODE_IS_IN_SHADOW_TREE) &&
@@ -7801,10 +7798,10 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
     //XXXsmaug This is super unefficient!
     nsIContent* bindingParent = aContainer->GetBindingParent();
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(bindingParent, false,
-                                           REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(bindingParent, false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   // Put 'parentFrame' inside a scope so we don't confuse it with
@@ -7815,7 +7812,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
     // a parent. While its uncommon to change the structure of the default content itself, a label,
     // for example, can be reframed by having its value attribute set or removed.
     if (!parentFrame && !aContainer->IsActiveChildrenElement()) {
-      return NS_OK;
+      return;
     }
 
     // Otherwise, we've got parent content. Find its frame.
@@ -7824,7 +7821,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
 
     if (aAllowLazyConstruction &&
         MaybeConstructLazily(CONTENTINSERT, aContainer, aStartChild)) {
-      return NS_OK;
+      return;
     }
   }
 
@@ -7844,7 +7841,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
   }
 
   if (!insertion.mParentFrame) {
-    return NS_OK;
+    return;
   }
 
   bool isAppend, isRangeInsertSafe;
@@ -7858,7 +7855,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
     IssueSingleInsertNofications(aContainer, aStartChild, aEndChild,
                                  aAllowLazyConstruction);
     LAYOUT_PHASE_TEMP_REENTER();
-    return NS_OK;
+    return;
   }
 
   nsIContent* container = insertion.mParentFrame->GetContent();
@@ -7867,7 +7864,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
   LAYOUT_PHASE_TEMP_EXIT();
   if (MaybeRecreateForFrameset(insertion.mParentFrame, aStartChild, aEndChild)) {
     LAYOUT_PHASE_TEMP_REENTER();
-    return NS_OK;
+    return;
   }
   LAYOUT_PHASE_TEMP_REENTER();
 
@@ -7884,10 +7881,10 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
     // and if so, proceed. But we'd have to extend nsFieldSetFrame
     // to locate this legend in the inserted frames and extract it.
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(insertion.mParentFrame->GetContent(), false,
-                                           REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(insertion.mParentFrame->GetContent(), false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   // We should only get here with details when doing a single insertion because
@@ -7899,26 +7896,25 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
     // expensive to recreate the entire details frame, but it's the simplest way
     // to handle the insertion.
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv =
-      RecreateFramesForContent(insertion.mParentFrame->GetContent(), false,
-                               REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(insertion.mParentFrame->GetContent(), false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   // Don't construct kids of leaves
   if (insertion.mParentFrame->IsLeaf()) {
     // Clear lazy bits so we don't try to construct again.
     ClearLazyBits(aStartChild, aEndChild);
-    return NS_OK;
+    return;
   }
 
   if (insertion.mParentFrame->IsFrameOfType(nsIFrame::eMathML)) {
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(insertion.mParentFrame->GetContent(), false,
-                                           REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(insertion.mParentFrame->GetContent(), false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   nsFrameConstructorState state(mPresShell,
@@ -7995,7 +7991,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
         IssueSingleInsertNofications(aContainer, aStartChild, aEndChild,
                                      aAllowLazyConstruction);
         LAYOUT_PHASE_TEMP_REENTER();
-        return NS_OK;
+        return;
       }
 
       container = insertion.mParentFrame->GetContent();
@@ -8063,7 +8059,7 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
   if (WipeContainingBlock(state, containingBlock, insertion.mParentFrame, items,
                           isAppend, prevSibling)) {
     LAYOUT_PHASE_TEMP_REENTER();
-    return NS_OK;
+    return;
   }
   LAYOUT_PHASE_TEMP_REENTER();
 
@@ -8235,10 +8231,10 @@ nsCSSFrameConstructor::ContentRangeInserted(nsIContent*            aContainer,
   }
 #endif
 
-  return NS_OK;
+  return;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
                                       nsIContent*  aChild,
                                       nsIContent*  aOldNextSibling,
@@ -8286,7 +8282,6 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
   }
 #endif
 
-  nsresult rv = NS_OK;
   nsIFrame* childFrame = aChild->GetPrimaryFrame();
   if (!childFrame || childFrame->GetContent() != aChild) {
     // XXXbz the GetContent() != aChild check is needed due to bug 135040.
@@ -8314,7 +8309,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
         // XXX Perhaps even only those that belong to the aChild sub-tree?
         RecreateFramesForContent(ancestor, false, aFlags, aDestroyedFramesFor);
         LAYOUT_PHASE_TEMP_REENTER();
-        return NS_OK;
+        return;
       }
     }
 
@@ -8322,11 +8317,10 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
     for (nsIContent* c = iter.GetNextChild(); c; c = iter.GetNextChild()) {
       if (c->GetPrimaryFrame() || GetDisplayContentsStyleFor(c)) {
         LAYOUT_PHASE_TEMP_EXIT();
-        rv = ContentRemoved(aChild, c, nullptr, aFlags, aDidReconstruct, aDestroyedFramesFor);
+        ContentRemoved(aChild, c, nullptr, aFlags, aDidReconstruct, aDestroyedFramesFor);
         LAYOUT_PHASE_TEMP_REENTER();
-        NS_ENSURE_SUCCESS(rv, rv);
         if (aFlags != REMOVE_DESTROY_FRAMES && *aDidReconstruct) {
-          return rv;
+          return;
         }
       }
     }
@@ -8339,7 +8333,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
     if (aFlags == REMOVE_DESTROY_FRAMES) {
       CaptureStateForFramesOf(aChild, mTempFrameTreeState);
     }
-    return NS_OK;
+    return;
   }
 
 #endif // MOZ_XUL
@@ -8377,10 +8371,9 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
     nsIContent* bindingParent = aContainer->GetBindingParent();
     *aDidReconstruct = true;
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(bindingParent, false,
-                                           aFlags, aDestroyedFramesFor);
+    RecreateFramesForContent(bindingParent, false, aFlags, aDestroyedFramesFor);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   if (aFlags == REMOVE_DESTROY_FRAMES) {
@@ -8393,14 +8386,14 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
     // See whether we need to remove more than just childFrame
     LAYOUT_PHASE_TEMP_EXIT();
     nsIContent* container;
-    if (MaybeRecreateContainerForFrameRemoval(childFrame, aFlags, &rv, &container)) {
+    if (MaybeRecreateContainerForFrameRemoval(childFrame, aFlags, &container)) {
       LAYOUT_PHASE_TEMP_REENTER();
       MOZ_ASSERT(container);
       *aDidReconstruct = true;
       if (aDestroyedFramesFor) {
         *aDestroyedFramesFor = container;
       }
-      return rv;
+      return;
     }
     LAYOUT_PHASE_TEMP_REENTER();
 
@@ -8413,10 +8406,10 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
       // Just reframe the parent, since framesets are weird like that.
       *aDidReconstruct = true;
       LAYOUT_PHASE_TEMP_EXIT();
-      nsresult rv = RecreateFramesForContent(parentFrame->GetContent(), false,
-                                             aFlags, aDestroyedFramesFor);
+      RecreateFramesForContent(parentFrame->GetContent(), false,
+                               aFlags, aDestroyedFramesFor);
       LAYOUT_PHASE_TEMP_REENTER();
-      return rv;
+      return;
     }
 
     // If we're a child of MathML, then we should reframe the MathML content.
@@ -8427,10 +8420,10 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
     if (possibleMathMLAncestor->IsFrameOfType(nsIFrame::eMathML)) {
       *aDidReconstruct = true;
       LAYOUT_PHASE_TEMP_EXIT();
-      nsresult rv = RecreateFramesForContent(possibleMathMLAncestor->GetContent(),
-                                             false, aFlags, aDestroyedFramesFor);
+      RecreateFramesForContent(possibleMathMLAncestor->GetContent(),
+                               false, aFlags, aDestroyedFramesFor);
       LAYOUT_PHASE_TEMP_REENTER();
-      return rv;
+      return;
     }
 
     // Undo XUL wrapping if it's no longer needed.
@@ -8444,10 +8437,10 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
         !AnyKidsNeedBlockParent(childFrame->GetNextSibling())) {
       *aDidReconstruct = true;
       LAYOUT_PHASE_TEMP_EXIT();
-      nsresult rv = RecreateFramesForContent(grandparentFrame->GetContent(), true,
-                                             aFlags, aDestroyedFramesFor);
+      RecreateFramesForContent(grandparentFrame->GetContent(), true,
+                               aFlags, aDestroyedFramesFor);
       LAYOUT_PHASE_TEMP_REENTER();
-      return rv;
+      return;
     }
 
 #ifdef ACCESSIBILITY
@@ -8491,7 +8484,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
         // XXXbz the GetContent() != aChild check is needed due to bug 135040.
         // Remove it once that's fixed.
         ClearUndisplayedContentIn(aChild, aContainer);
-        return NS_OK;
+        return;
       }
       parentFrame = childFrame->GetParent();
       parentType = parentFrame->GetType();
@@ -8581,7 +8574,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent*  aContainer,
 #endif
   }
 
-  return rv;
+  return;
 }
 
 /**
@@ -8643,12 +8636,11 @@ nsCSSFrameConstructor::EnsureFrameForTextNode(nsGenericDOMDataNode* aContent)
   return aContent->GetPrimaryFrame();
 }
 
-nsresult
+void
 nsCSSFrameConstructor::CharacterDataChanged(nsIContent* aContent,
                                             CharacterDataChangeInfo* aInfo)
 {
   AUTO_LAYOUT_PHASE_ENTRY_POINT(mPresShell->GetPresContext(), FrameC);
-  nsresult      rv = NS_OK;
 
   if ((aContent->HasFlag(NS_CREATE_FRAME_IF_NON_WHITESPACE) &&
        !aContent->TextIsOnlyWhitespace()) ||
@@ -8660,10 +8652,10 @@ nsCSSFrameConstructor::CharacterDataChanged(nsIContent* aContent,
                  "Bit should never be set on generated content");
 #endif
     LAYOUT_PHASE_TEMP_EXIT();
-    nsresult rv = RecreateFramesForContent(aContent, false,
-                                           REMOVE_FOR_RECONSTRUCTION, nullptr);
+    RecreateFramesForContent(aContent, false,
+                             REMOVE_FOR_RECONSTRUCTION, nullptr);
     LAYOUT_PHASE_TEMP_REENTER();
-    return rv;
+    return;
   }
 
   // Find the child frame
@@ -8711,8 +8703,6 @@ nsCSSFrameConstructor::CharacterDataChanged(nsIContent* aContent,
       RecoverLetterFrames(block);
     }
   }
-
-  return rv;
 }
 
 void
@@ -9371,12 +9361,10 @@ FindPreviousNonWhitespaceSibling(nsIFrame* aFrame)
 bool
 nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
                                                              RemoveFlags aFlags,
-                                                             nsresult* aResult,
                                                              nsIContent** aDestroyedFramesFor)
 {
   NS_PRECONDITION(aFrame, "Must have a frame");
   NS_PRECONDITION(aFrame->GetParent(), "Frame shouldn't be root");
-  NS_PRECONDITION(aResult, "Null out param?");
   NS_PRECONDITION(aFrame == aFrame->FirstContinuation(),
                   "aFrame not the result of GetPrimaryFrame()?");
 
@@ -9394,7 +9382,7 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
     }
 #endif
 
-    *aResult = ReframeContainingBlock(aFrame, aFlags, aDestroyedFramesFor);
+    ReframeContainingBlock(aFrame, aFlags, aDestroyedFramesFor);
     return true;
   }
 
@@ -9403,8 +9391,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
       aFrame->GetParent()->GetType() == nsGkAtoms::fieldSetFrame) {
     // When we remove the legend for a fieldset, we should reframe
     // the fieldset to ensure another legend is used, if there is one
-    *aResult = RecreateFramesForContent(aFrame->GetParent()->GetContent(), false,
-                                        aFlags, aDestroyedFramesFor);
+    RecreateFramesForContent(aFrame->GetParent()->GetContent(), false,
+                             aFlags, aDestroyedFramesFor);
     return true;
   }
 
@@ -9417,9 +9405,9 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
       // When removing a summary, we should reframe the parent details frame to
       // ensure that another summary is used or the default summary is
       // generated.
-      *aResult = RecreateFramesForContent(aFrame->GetParent()->GetContent(),
-                                          false, REMOVE_FOR_RECONSTRUCTION,
-                                          aDestroyedFramesFor);
+      RecreateFramesForContent(aFrame->GetParent()->GetContent(),
+                               false, REMOVE_FOR_RECONSTRUCTION,
+                               aDestroyedFramesFor);
       return true;
     }
   }
@@ -9451,8 +9439,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
          parent->GetChildList(nsIFrame::kCaptionList).FirstChild() == inFlowFrame)) {
       // We're the first or last frame in the pseudo.  Need to reframe.
       // Good enough to recreate frames for |parent|'s content
-      *aResult = RecreateFramesForContent(parent->GetContent(), true, aFlags,
-                                          aDestroyedFramesFor);
+      RecreateFramesForContent(parent->GetContent(), true, aFlags,
+                               aDestroyedFramesFor);
       return true;
     }
   }
@@ -9481,8 +9469,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
 #endif
       // Good enough to recreate frames for aFrame's parent's content; even if
       // aFrame's parent is a pseudo, that'll be the right content node.
-      *aResult = RecreateFramesForContent(parent->GetContent(), true, aFlags,
-                                          aDestroyedFramesFor);
+      RecreateFramesForContent(parent->GetContent(), true, aFlags,
+                               aDestroyedFramesFor);
       return true;
     }
   }
@@ -9498,8 +9486,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
     //    frames may be constructed or destroyed accordingly.
     // 2. The type of the first child of a ruby frame determines
     //    whether a pseudo ruby base container should exist.
-    *aResult = RecreateFramesForContent(parent->GetContent(), true, aFlags,
-                                        aDestroyedFramesFor);
+    RecreateFramesForContent(parent->GetContent(), true, aFlags,
+                             aDestroyedFramesFor);
     return true;
   }
 
@@ -9522,8 +9510,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
     }
 #endif // DEBUG
     // Recreate frames for the flex container (the removed frame's parent)
-    *aResult = RecreateFramesForContent(parent->GetContent(), true, aFlags,
-                                        aDestroyedFramesFor);
+    RecreateFramesForContent(parent->GetContent(), true, aFlags,
+                             aDestroyedFramesFor);
     return true;
   }
 
@@ -9541,8 +9529,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
     }
 #endif // DEBUG
     // Recreate frames for the flex container (the removed frame's grandparent)
-    *aResult = RecreateFramesForContent(parent->GetParent()->GetContent(), true,
-                                        aFlags, aDestroyedFramesFor);
+    RecreateFramesForContent(parent->GetParent()->GetContent(), true,
+                             aFlags, aDestroyedFramesFor);
     return true;
   }
 
@@ -9550,7 +9538,7 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
   if (aFrame->GetType() == nsGkAtoms::popupSetFrame) {
     nsIRootBox* rootBox = nsIRootBox::GetRootBox(mPresShell);
     if (rootBox && rootBox->GetPopupSetFrame() == aFrame) {
-      *aResult = ReconstructDocElementHierarchy();
+      ReconstructDocElementHierarchy();
       return true;
     }
   }
@@ -9562,8 +9550,8 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
       !inFlowFrame->GetNextSibling() &&
       ((parent->GetPrevContinuation() && !parent->GetPrevInFlow()) ||
        (parent->GetNextContinuation() && !parent->GetNextInFlow()))) {
-    *aResult = RecreateFramesForContent(parent->GetContent(), true, aFlags,
-                                        aDestroyedFramesFor);
+    RecreateFramesForContent(parent->GetContent(), true, aFlags,
+                             aDestroyedFramesFor);
     return true;
   }
 
@@ -9599,11 +9587,11 @@ nsCSSFrameConstructor::MaybeRecreateContainerForFrameRemoval(nsIFrame* aFrame,
   }
 #endif
 
-  *aResult = ReframeContainingBlock(parent, aFlags, aDestroyedFramesFor);
+  ReframeContainingBlock(parent, aFlags, aDestroyedFramesFor);
   return true;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::RecreateFramesForContent(nsIContent*  aContent,
                                                 bool         aAsyncInsert,
                                                 RemoveFlags  aFlags,
@@ -9616,7 +9604,9 @@ nsCSSFrameConstructor::RecreateFramesForContent(nsIContent*  aContent,
   // anyway).
   // Rebuilding the frame tree can have bad effects, especially if it's the
   // frame tree for chrome (see bug 157322).
-  NS_ENSURE_TRUE(aContent->GetComposedDoc(), NS_ERROR_FAILURE);
+  if (NS_WARN_IF(!aContent->GetComposedDoc())) {
+    return;
+  }
 
   // Is the frame ib-split? If so, we need to reframe the containing
   // block *here*, rather than trying to remove and re-insert the
@@ -9680,15 +9670,14 @@ nsCSSFrameConstructor::RecreateFramesForContent(nsIContent*  aContent,
     }
   }
 
-  nsresult rv = NS_OK;
   nsIContent* container;
-  if (frame && MaybeRecreateContainerForFrameRemoval(frame, aFlags, &rv,
+  if (frame && MaybeRecreateContainerForFrameRemoval(frame, aFlags,
                                                      &container)) {
     MOZ_ASSERT(container);
     if (aDestroyedFramesFor) {
       *aDestroyedFramesFor = container;
     }
-    return rv;
+    return;
   }
 
   nsINode* containerNode = aContent->GetParentNode();
@@ -9708,11 +9697,8 @@ nsCSSFrameConstructor::RecreateFramesForContent(nsIContent*  aContent,
       nullptr : aContent->GetNextSibling();
     const bool reconstruct = aFlags != REMOVE_DESTROY_FRAMES;
     RemoveFlags flags = reconstruct ? REMOVE_FOR_RECONSTRUCTION : aFlags;
-    rv = ContentRemoved(container, aContent, nextSibling, flags,
-                        &didReconstruct, aDestroyedFramesFor);
-    if (NS_FAILED(rv)) {
-      return rv;
-    }
+    ContentRemoved(container, aContent, nextSibling, flags,
+                   &didReconstruct, aDestroyedFramesFor);
     if (reconstruct && !didReconstruct) {
       // Now, recreate the frames associated with this content object. If
       // ContentRemoved triggered reconstruction, then we don't need to do this
@@ -9722,12 +9708,10 @@ nsCSSFrameConstructor::RecreateFramesForContent(nsIContent*  aContent,
         RestyleManager()->PostRestyleEvent(
           aContent->AsElement(), nsRestyleHint(0), nsChangeHint_ReconstructFrame);
       } else {
-        rv = ContentInserted(container, aContent, mTempFrameTreeState, false);
+        ContentInserted(container, aContent, mTempFrameTreeState, false);
       }
     }
   }
-
-  return rv;
 }
 
 void
@@ -11123,7 +11107,7 @@ nsCSSFrameConstructor::AppendFirstLineFrames(
 // Special routine to handle inserting a new frame into a block
 // frame's child list. Takes care of placing the new frame into the
 // right place when first-line style is present.
-nsresult
+void
 nsCSSFrameConstructor::InsertFirstLineFrames(
   nsFrameConstructorState& aState,
   nsIContent*              aContent,
@@ -11132,7 +11116,6 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
   nsIFrame*                aPrevSibling,
   nsFrameItems&            aFrameItems)
 {
-  nsresult rv = NS_OK;
   // XXXbz If you make this method actually do something, check to
   // make sure that the caller is passing what you expect.  In
   // particular, which content is aContent?  And audit the rest of
@@ -11262,7 +11245,6 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
   }
 
 #endif
-  return rv;
 }
 
 //----------------------------------------------------------------------
@@ -11586,7 +11568,7 @@ FindFirstLetterFrame(nsIFrame* aFrame, nsIFrame::ChildListID aListID)
   return nullptr;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   nsIPresShell* aPresShell,
   nsIFrame* aBlockFrame)
@@ -11598,7 +11580,7 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
     floatFrame =
       ::FindFirstLetterFrame(aBlockFrame, nsIFrame::kPushedFloatsList);
     if (!floatFrame) {
-      return NS_OK;
+      return;
     }
   }
 
@@ -11606,19 +11588,19 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   // destroyed when we destroy the letter frame).
   nsIFrame* textFrame = floatFrame->PrincipalChildList().FirstChild();
   if (!textFrame) {
-    return NS_OK;
+    return;
   }
 
   // Discover the placeholder frame for the letter frame
   nsPlaceholderFrame* placeholderFrame = GetPlaceholderFrameFor(floatFrame);
   if (!placeholderFrame) {
     // Somethings really wrong
-    return NS_OK;
+    return;
   }
   nsContainerFrame* parentFrame = placeholderFrame->GetParent();
   if (!parentFrame) {
     // Somethings really wrong
-    return NS_OK;
+    return;
   }
 
   // Create a new text frame with the right style context that maps
@@ -11627,7 +11609,7 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   nsStyleContext* parentSC = parentFrame->StyleContext();
   nsIContent* textContent = textFrame->GetContent();
   if (!textContent) {
-    return NS_OK;
+    return;
   }
   RefPtr<nsStyleContext> newSC = aPresShell->StyleSet()->
     ResolveStyleForText(textContent, parentSC);
@@ -11672,11 +11654,9 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   if (offsetsNeedFixing) {
     prevSibling->RemoveStateBits(TEXT_OFFSETS_NEED_FIXING);
   }
-
-  return NS_OK;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::RemoveFirstLetterFrames(nsIPresShell* aPresShell,
                                                nsContainerFrame* aFrame,
                                                nsContainerFrame* aBlockFrame,
@@ -11749,11 +11729,9 @@ nsCSSFrameConstructor::RemoveFirstLetterFrames(nsIPresShell* aPresShell,
     prevSibling = kid;
     kid = kid->GetNextSibling();
   }
-
-  return NS_OK;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::RemoveLetterFrames(nsIPresShell* aPresShell,
                                           nsContainerFrame* aBlockFrame)
 {
@@ -11762,20 +11740,16 @@ nsCSSFrameConstructor::RemoveLetterFrames(nsIPresShell* aPresShell,
   nsContainerFrame* continuation = aBlockFrame;
 
   bool stopLooking = false;
-  nsresult rv;
   do {
-    rv = RemoveFloatingFirstLetterFrames(aPresShell, continuation);
-    if (NS_SUCCEEDED(rv)) {
-      rv = RemoveFirstLetterFrames(aPresShell,
-                                   continuation, aBlockFrame, &stopLooking);
-    }
+    RemoveFloatingFirstLetterFrames(aPresShell, continuation);
+    RemoveFirstLetterFrames(aPresShell, continuation, aBlockFrame,
+                            &stopLooking);
     if (stopLooking) {
       break;
     }
     continuation =
       static_cast<nsContainerFrame*>(continuation->GetNextContinuation());
   }  while (continuation);
-  return rv;
 }
 
 // Fixup the letter frame situation for the given block
@@ -11818,7 +11792,7 @@ nsCSSFrameConstructor::RecoverLetterFrames(nsContainerFrame* aBlockFrame)
 
 // listbox Widget Routines
 
-nsresult
+void
 nsCSSFrameConstructor::CreateListBoxContent(nsContainerFrame*      aParentFrame,
                                             nsIFrame*              aPrevFrame,
                                             nsIContent*            aChild,
@@ -11826,8 +11800,6 @@ nsCSSFrameConstructor::CreateListBoxContent(nsContainerFrame*      aParentFrame,
                                             bool                   aIsAppend)
 {
 #ifdef MOZ_XUL
-  nsresult rv = NS_OK;
-
   // Construct a new frame
   if (nullptr != aParentFrame) {
     nsFrameItems            frameItems;
@@ -11848,7 +11820,7 @@ nsCSSFrameConstructor::CreateListBoxContent(nsContainerFrame*      aParentFrame,
 
     if (StyleDisplay::None == display->mDisplay) {
       *aNewFrame = nullptr;
-      return NS_OK;
+      return;
     }
 
     BeginUpdate();
@@ -11867,9 +11839,9 @@ nsCSSFrameConstructor::CreateListBoxContent(nsContainerFrame*      aParentFrame,
     if (newFrame) {
       // Notify the parent frame
       if (aIsAppend)
-        rv = ((nsListBoxBodyFrame*)aParentFrame)->ListBoxAppendFrames(frameItems);
+        ((nsListBoxBodyFrame*)aParentFrame)->ListBoxAppendFrames(frameItems);
       else
-        rv = ((nsListBoxBodyFrame*)aParentFrame)->ListBoxInsertFrames(aPrevFrame, frameItems);
+        ((nsListBoxBodyFrame*)aParentFrame)->ListBoxInsertFrames(aPrevFrame, frameItems);
     }
 
     EndUpdate();
@@ -11884,10 +11856,6 @@ nsCSSFrameConstructor::CreateListBoxContent(nsContainerFrame*      aParentFrame,
     }
 #endif
   }
-
-  return rv;
-#else
-  return NS_ERROR_FAILURE;
 #endif
 }
 
@@ -12659,7 +12627,7 @@ nsCSSFrameConstructor::WipeContainingBlock(nsFrameConstructorState& aState,
   return true;
 }
 
-nsresult
+void
 nsCSSFrameConstructor::ReframeContainingBlock(nsIFrame*    aFrame,
                                               RemoveFlags  aFlags,
                                               nsIContent** aDestroyedFramesFor)
@@ -12682,7 +12650,7 @@ nsCSSFrameConstructor::ReframeContainingBlock(nsIFrame*    aFrame,
     // don't ReframeContainingBlock, this will result in a crash
     // if we remove a tree that's in reflow - see bug 121368 for testcase
     NS_ERROR("Atemptted to nsCSSFrameConstructor::ReframeContainingBlock during a Reflow!!!");
-    return NS_OK;
+    return;
   }
 
   // Get the first "normal" ancestor of the target frame.
@@ -12714,7 +12682,7 @@ nsCSSFrameConstructor::ReframeContainingBlock(nsIFrame*    aFrame,
                                   true, aFlags, nullptr);
 }
 
-nsresult
+void
 nsCSSFrameConstructor::GenerateChildFrames(nsContainerFrame* aFrame)
 {
   {
@@ -12748,8 +12716,6 @@ nsCSSFrameConstructor::GenerateChildFrames(nsContainerFrame* aFrame)
 
   // call XBL constructors after the frames are created
   mPresShell->GetDocument()->BindingManager()->ProcessAttachedQueue();
-
-  return NS_OK;
 }
 
 //////////////////////////////////////////////////////////
diff --git a/layout/base/nsCSSFrameConstructor.h b/layout/base/nsCSSFrameConstructor.h
index db0d92566b..655519e0f6 100644
--- a/layout/base/nsCSSFrameConstructor.h
+++ b/layout/base/nsCSSFrameConstructor.h
@@ -48,7 +48,7 @@ class FlattenedChildIterator;
 } // namespace dom
 } // namespace mozilla
 
-class nsCSSFrameConstructor : public nsFrameManager
+class nsCSSFrameConstructor final : public nsFrameManager
 {
 public:
   typedef mozilla::CSSPseudoElementType CSSPseudoElementType;
@@ -60,7 +60,7 @@ public:
 
   nsCSSFrameConstructor(nsIDocument* aDocument, nsIPresShell* aPresShell);
   ~nsCSSFrameConstructor(void) {
-    NS_ASSERTION(mUpdateCount == 0, "Dying in the middle of our own update?");
+    MOZ_ASSERT(mUpdateCount == 0, "Dying in the middle of our own update?");
   }
 
   // get the alternate text for a content node
@@ -78,7 +78,7 @@ public:
 
   nsIFrame* ConstructRootFrame();
 
-  nsresult ReconstructDocElementHierarchy();
+  void ReconstructDocElementHierarchy();
 
   // Create frames for content nodes that are marked as needing frames. This
   // should be called before ProcessPendingRestyles.
@@ -202,16 +202,16 @@ public:
 
   // If aAllowLazyConstruction is true then frame construction of the new
   // children can be done lazily.
-  nsresult ContentAppended(nsIContent* aContainer,
-                           nsIContent* aFirstNewContent,
-                           bool        aAllowLazyConstruction);
+  void ContentAppended(nsIContent* aContainer,
+                       nsIContent* aFirstNewContent,
+                       bool aAllowLazyConstruction);
 
   // If aAllowLazyConstruction is true then frame construction of the new child
   // can be done lazily.
-  nsresult ContentInserted(nsIContent*            aContainer,
-                           nsIContent*            aChild,
-                           nsILayoutHistoryState* aFrameState,
-                           bool                   aAllowLazyConstruction);
+  void ContentInserted(nsIContent* aContainer,
+                       nsIContent* aChild,
+                       nsILayoutHistoryState* aFrameState,
+                       bool aAllowLazyConstruction);
 
   // Like ContentInserted but handles inserting the children of aContainer in
   // the range [aStartChild, aEndChild).  aStartChild must be non-null.
@@ -219,11 +219,11 @@ public:
   // aStartChild.  If aAllowLazyConstruction is true then frame construction of
   // the new children can be done lazily. It is only allowed to be true when
   // inserting a single node.
-  nsresult ContentRangeInserted(nsIContent*            aContainer,
-                                nsIContent*            aStartChild,
-                                nsIContent*            aEndChild,
-                                nsILayoutHistoryState* aFrameState,
-                                bool                   aAllowLazyConstruction);
+  void ContentRangeInserted(nsIContent* aContainer,
+                            nsIContent* aStartChild,
+                            nsIContent* aEndChild,
+                            nsILayoutHistoryState* aFrameState,
+                            bool aAllowLazyConstruction);
 
   enum RemoveFlags {
     REMOVE_CONTENT, REMOVE_FOR_RECONSTRUCTION, REMOVE_DESTROY_FRAMES };
@@ -243,15 +243,15 @@ public:
    * only when aFlags == REMOVE_DESTROY_FRAMES, otherwise it will only be
    * captured if we reconstructed frames for an ancestor.
    */
-  nsresult ContentRemoved(nsIContent*  aContainer,
-                          nsIContent*  aChild,
-                          nsIContent*  aOldNextSibling,
-                          RemoveFlags  aFlags,
-                          bool*        aDidReconstruct,
-                          nsIContent** aDestroyedFramesFor = nullptr);
+  void ContentRemoved(nsIContent*  aContainer,
+                      nsIContent*  aChild,
+                      nsIContent*  aOldNextSibling,
+                      RemoveFlags  aFlags,
+                      bool*        aDidReconstruct,
+                      nsIContent** aDestroyedFramesFor = nullptr);
 
-  nsresult CharacterDataChanged(nsIContent* aContent,
-                                CharacterDataChangeInfo* aInfo);
+  void CharacterDataChanged(nsIContent* aContent,
+                            CharacterDataChangeInfo* aInfo);
 
   // If aContent is a text node that has been optimized away due to being
   // whitespace next to a block boundary (or for some other reason), stop
@@ -260,8 +260,8 @@ public:
   // Returns the frame for aContent if there is one.
   nsIFrame* EnsureFrameForTextNode(nsGenericDOMDataNode* aContent);
 
-  // generate the child frames and process bindings
-  nsresult GenerateChildFrames(nsContainerFrame* aFrame);
+  // Generate the child frames and process bindings
+  void GenerateChildFrames(nsContainerFrame* aFrame);
 
   // Should be called when a frame is going to be destroyed and
   // WillDestroyFrameTree hasn't been called yet.
@@ -303,11 +303,11 @@ public:
    */
   InsertionPoint GetInsertionPoint(nsIContent* aContainer, nsIContent* aChild);
 
-  nsresult CreateListBoxContent(nsContainerFrame* aParentFrame,
-                                nsIFrame*         aPrevFrame,
-                                nsIContent*       aChild,
-                                nsIFrame**        aResult,
-                                bool              aIsAppend);
+  void CreateListBoxContent(nsContainerFrame* aParentFrame,
+                            nsIFrame*         aPrevFrame,
+                            nsIContent*       aChild,
+                            nsIFrame**        aResult,
+                            bool              aIsAppend);
 
   // GetInitialContainingBlock() is deprecated in favor of GetRootElementFrame();
   // nsIFrame* GetInitialContainingBlock() { return mRootElementFrame; }
@@ -419,14 +419,14 @@ private:
    * @param [out] aNewContent the content node we create
    * @param [out] aNewFrame the new frame we create
    */
-  nsresult CreateAttributeContent(nsIContent* aParentContent,
-                                  nsIFrame* aParentFrame,
-                                  int32_t aAttrNamespace,
-                                  nsIAtom* aAttrName,
-                                  nsStyleContext* aStyleContext,
-                                  nsCOMArray<nsIContent>& aGeneratedContent,
-                                  nsIContent** aNewContent,
-                                  nsIFrame** aNewFrame);
+  void CreateAttributeContent(nsIContent* aParentContent,
+                              nsIFrame* aParentFrame,
+                              int32_t aAttrNamespace,
+                              nsIAtom* aAttrName,
+                              nsStyleContext* aStyleContext,
+                              nsCOMArray<nsIContent>& aGeneratedContent,
+                              nsIContent** aNewContent,
+                              nsIFrame** aNewFrame);
 
   /**
    * Create a text node containing the given string. If aText is non-null
@@ -464,11 +464,11 @@ private:
   // aParentFrame.  aPrevSibling must be the frame after which aFrameList is to
   // be placed on aParentFrame's principal child list.  It may be null if
   // aFrameList is being added at the beginning of the child list.
-  nsresult AppendFramesToParent(nsFrameConstructorState&       aState,
-                                nsContainerFrame*              aParentFrame,
-                                nsFrameItems&                  aFrameList,
-                                nsIFrame*                      aPrevSibling,
-                                bool                           aIsRecursiveCall = false);
+  void AppendFramesToParent(nsFrameConstructorState&       aState,
+                            nsContainerFrame*              aParentFrame,
+                            nsFrameItems&                  aFrameList,
+                            nsIFrame*                      aPrevSibling,
+                            bool                           aIsRecursiveCall = false);
 
   // BEGIN TABLE SECTION
   /**
@@ -1692,7 +1692,7 @@ private:
   // InitializeSelectFrame puts scrollFrame in aFrameItems if aBuildCombobox is false
   // aBuildCombobox indicates if we are building a combobox that has a dropdown
   // popup widget or not.
-  nsresult
+  void
   InitializeSelectFrame(nsFrameConstructorState& aState,
                         nsContainerFrame*        aScrollFrame,
                         nsContainerFrame*        aScrolledFrame,
@@ -1721,7 +1721,7 @@ private:
    * @param aDestroyedFramesFor if non-null, it will contain the content that
    *   was actually reframed - it may be different than aContent.
    */
-  nsresult
+  void
   RecreateFramesForContent(nsIContent*  aContent,
                            bool         aAsyncInsert,
                            RemoveFlags  aFlags,
@@ -1739,7 +1739,6 @@ private:
   // content that was reframed.
   bool MaybeRecreateContainerForFrameRemoval(nsIFrame*    aFrame,
                                              RemoveFlags  aFlags,
-                                             nsresult*    aResult,
                                              nsIContent** aDestroyedFramesFor);
 
   nsIFrame* CreateContinuingOuterTableFrame(nsIPresShell*     aPresShell,
@@ -1864,9 +1863,9 @@ private:
                              bool                     aIsAppend,
                              nsIFrame*                aPrevSibling);
 
-  nsresult ReframeContainingBlock(nsIFrame*    aFrame,
-                                  RemoveFlags  aFlags,
-                                  nsIContent** aReframeContent);
+  void ReframeContainingBlock(nsIFrame*    aFrame,
+                              RemoveFlags  aFlags,
+                              nsIContent** aReframeContent);
 
   //----------------------------------------
 
@@ -1920,18 +1919,18 @@ private:
   void RecoverLetterFrames(nsContainerFrame* aBlockFrame);
 
   //
-  nsresult RemoveLetterFrames(nsIPresShell*     aPresShell,
-                              nsContainerFrame* aBlockFrame);
+  void RemoveLetterFrames(nsIPresShell*     aPresShell,
+                          nsContainerFrame* aBlockFrame);
 
   // Recursive helper for RemoveLetterFrames
-  nsresult RemoveFirstLetterFrames(nsIPresShell*     aPresShell,
-                                   nsContainerFrame* aFrame,
-                                   nsContainerFrame* aBlockFrame,
-                                   bool*             aStopLooking);
+  void RemoveFirstLetterFrames(nsIPresShell*     aPresShell,
+                               nsContainerFrame* aFrame,
+                               nsContainerFrame* aBlockFrame,
+                               bool*             aStopLooking);
 
   // Special remove method for those pesky floating first-letter frames
-  nsresult RemoveFloatingFirstLetterFrames(nsIPresShell*    aPresShell,
-                                           nsIFrame*        aBlockFrame);
+  void RemoveFloatingFirstLetterFrames(nsIPresShell*    aPresShell,
+                                       nsIFrame*        aBlockFrame);
 
   // Capture state for the frame tree rooted at the frame associated with the
   // content object, aContent
@@ -1962,12 +1961,12 @@ private:
                              nsContainerFrame*        aBlockFrame,
                              nsFrameItems&            aFrameItems);
 
-  nsresult InsertFirstLineFrames(nsFrameConstructorState& aState,
-                                 nsIContent*              aContent,
-                                 nsIFrame*                aBlockFrame,
-                                 nsContainerFrame**       aParentFrame,
-                                 nsIFrame*                aPrevSibling,
-                                 nsFrameItems&            aFrameItems);
+  void InsertFirstLineFrames(nsFrameConstructorState& aState,
+                             nsIContent*              aContent,
+                             nsIFrame*                aBlockFrame,
+                             nsContainerFrame**       aParentFrame,
+                             nsIFrame*                aPrevSibling,
+                             nsFrameItems&            aFrameItems);
 
   /**
    * Find the right frame to use for aContent when looking for sibling
diff --git a/layout/base/nsFrameManager.cpp b/layout/base/nsFrameManager.cpp
index 97b022da8b..6bcc715b91 100644
--- a/layout/base/nsFrameManager.cpp
+++ b/layout/base/nsFrameManager.cpp
@@ -38,13 +38,8 @@
 #include "nsIStatefulFrame.h"
 #include "nsContainerFrame.h"
 
-  #ifdef DEBUG
-    //#define DEBUG_UNDISPLAYED_MAP
-    //#define DEBUG_DISPLAY_CONTENTS_MAP
-  #else
-    #undef DEBUG_UNDISPLAYED_MAP
-    #undef DEBUG_DISPLAY_CONTENTS_MAP
-  #endif
+// #define DEBUG_UNDISPLAYED_MAP
+// #define DEBUG_DISPLAY_CONTENTS_MAP
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -87,40 +82,49 @@ nsFrameManagerBase::nsFrameManagerBase()
 
 //----------------------------------------------------------------------
 
-// XXXldb This seems too complicated for what I think it's doing, and it
-// should also be using PLDHashTable rather than plhash to use less memory.
+/**
+ * The undisplayed map is a class that maps a parent content node to the
+ * undisplayed content children, and their style contexts.
+ *
+ * The linked list of nodes holds strong references to the style contexts and
+ * the content.
+ */
+class nsFrameManagerBase::UndisplayedMap :
+  private nsClassHashtable<nsPtrHashKey<nsIContent>,
+                           LinkedList<UndisplayedNode>>
+{
+  typedef nsClassHashtable<nsPtrHashKey<nsIContent>, LinkedList<UndisplayedNode>> base_type;
 
-class nsFrameManagerBase::UndisplayedMap {
 public:
-  explicit UndisplayedMap(uint32_t aNumBuckets = 16);
-  ~UndisplayedMap(void);
+  UndisplayedMap();
+  ~UndisplayedMap();
 
   UndisplayedNode* GetFirstNode(nsIContent* aParentContent);
 
-  nsresult AddNodeFor(nsIContent* aParentContent,
-                                  nsIContent* aChild, nsStyleContext* aStyle);
+  void AddNodeFor(nsIContent* aParentContent,
+                  nsIContent* aChild,
+                  nsStyleContext* aStyle);
 
-  void RemoveNodeFor(nsIContent* aParentContent,
-                                 UndisplayedNode* aNode);
+  void RemoveNodeFor(nsIContent* aParentContent, UndisplayedNode* aNode);
 
   void RemoveNodesFor(nsIContent* aParentContent);
-  UndisplayedNode* UnlinkNodesFor(nsIContent* aParentContent);
+
+  nsAutoPtr<LinkedList<UndisplayedNode>>
+    UnlinkNodesFor(nsIContent* aParentContent);
 
   // Removes all entries from the hash table
-  void  Clear(void);
+  void  Clear();
 
 protected:
+  LinkedList<UndisplayedNode>* GetListFor(nsIContent** aParentContent);
+  LinkedList<UndisplayedNode>* GetOrCreateListFor(nsIContent** aParentContent);
+  void AppendNodeFor(UndisplayedNode* aNode, nsIContent* aParentContent);
   /**
-   * Gets the entry for the provided parent content. If the content
-   * is a <xbl:children> element, |**aParentContent| is set to
-   * the parent of the children element.
+   * Get the applicable parent for the map lookup. This is almost always the
+   * provided argument, except if it's a <xbl:children> element, in which case
+   * it's the parent of the children element.
    */
-  PLHashEntry** GetEntryFor(nsIContent** aParentContent);
-  void          AppendNodeFor(UndisplayedNode* aNode,
-                                          nsIContent* aParentContent);
-
-  PLHashTable*  mTable;
-  PLHashEntry** mLastLookup;
+  nsIContent* GetApplicableParent(nsIContent* aParent);
 };
 
 //----------------------------------------------------------------------
@@ -145,7 +149,6 @@ nsFrameManager::Destroy()
     mRootFrame->Destroy();
     mRootFrame = nullptr;
   }
-  
   delete mUndisplayedMap;
   mUndisplayedMap = nullptr;
   delete mDisplayContentsMap;
@@ -215,7 +218,7 @@ nsFrameManager::GetStyleContextInMap(UndisplayedMap* aMap, nsIContent* aContent)
   nsIContent* parent = aContent->GetParentElementCrossingShadowRoot();
   MOZ_ASSERT(parent || !aContent->GetParent(), "no non-elements");
   for (UndisplayedNode* node = aMap->GetFirstNode(parent);
-         node; node = node->mNext) {
+       node; node = node->getNext()) {
     if (node->mContent == aContent)
       return node->mStyle;
   }
@@ -241,16 +244,16 @@ nsFrameManager::SetStyleContextInMap(UndisplayedMap* aMap,
                                      nsIContent* aContent,
                                      nsStyleContext* aStyleContext)
 {
-  NS_PRECONDITION(!aStyleContext->GetPseudo(),
-                  "Should only have actual elements here");
+  MOZ_ASSERT(!aStyleContext->GetPseudo(),
+             "Should only have actual elements here");
 
 #if defined(DEBUG_UNDISPLAYED_MAP) || defined(DEBUG_DISPLAY_BOX_CONTENTS_MAP)
   static int i = 0;
   printf("SetStyleContextInMap(%d): p=%p \n", i++, (void *)aContent);
 #endif
 
-  NS_ASSERTION(!GetStyleContextInMap(aMap, aContent),
-               "Already have an entry for aContent");
+  MOZ_ASSERT(!GetStyleContextInMap(aMap, aContent),
+             "Already have an entry for aContent");
 
   nsIContent* parent = aContent->GetParentElementCrossingShadowRoot();
   MOZ_ASSERT(parent || !aContent->GetParent(), "no non-elements");
@@ -287,7 +290,7 @@ nsFrameManager::ChangeStyleContextInMap(UndisplayedMap* aMap,
 #endif
 
   for (UndisplayedNode* node = aMap->GetFirstNode(aContent->GetParent());
-         node; node = node->mNext) {
+       node; node = node->getNext()) {
     if (node->mContent == aContent) {
       node->mStyle = aStyleContext;
       return;
@@ -306,25 +309,25 @@ nsFrameManager::ClearUndisplayedContentIn(nsIContent* aContent,
   printf("ClearUndisplayedContent(%d): content=%p parent=%p --> ", i++, (void *)aContent, (void*)aParentContent);
 #endif
   
-  if (mUndisplayedMap) {
-    UndisplayedNode* node = mUndisplayedMap->GetFirstNode(aParentContent);
-    while (node) {
-      if (node->mContent == aContent) {
-        mUndisplayedMap->RemoveNodeFor(aParentContent, node);
+  if (!mUndisplayedMap) {
+    return;
+  }
+
+  for (UndisplayedNode* node = mUndisplayedMap->GetFirstNode(aParentContent);
+       node; node = node->getNext()) {
+    if (node->mContent == aContent) {
+      mUndisplayedMap->RemoveNodeFor(aParentContent, node);
 
 #ifdef DEBUG_UNDISPLAYED_MAP
-        printf( "REMOVED!\n");
-#endif
-#ifdef DEBUG
-        // make sure that there are no more entries for the same content
-        nsStyleContext *context = GetUndisplayedContent(aContent);
-        NS_ASSERTION(context == nullptr, "Found more undisplayed content data after removal");
+      printf( "REMOVED!\n");
 #endif
-        return;
-      }
-      node = node->mNext;
+      // make sure that there are no more entries for the same content
+      MOZ_ASSERT(!GetUndisplayedContent(aContent),
+                 "Found more undisplayed content data after removal");
+      return;
     }
   }
+
 #ifdef DEBUG_UNDISPLAYED_MAP
   printf( "not found.\n");
 #endif
@@ -380,26 +383,25 @@ nsFrameManager::ClearDisplayContentsIn(nsIContent* aContent,
   static int i = 0;
   printf("ClearDisplayContents(%d): content=%p parent=%p --> ", i++, (void *)aContent, (void*)aParentContent);
 #endif
-  
-  if (mDisplayContentsMap) {
-    UndisplayedNode* node = mDisplayContentsMap->GetFirstNode(aParentContent);
-    while (node) {
-      if (node->mContent == aContent) {
-        mDisplayContentsMap->RemoveNodeFor(aParentContent, node);
+
+  if (!mDisplayContentsMap) {
+    return;
+  }
+
+  for (UndisplayedNode* node = mDisplayContentsMap->GetFirstNode(aParentContent);
+       node; node = node->getNext()) {
+    if (node->mContent == aContent) {
+      mDisplayContentsMap->RemoveNodeFor(aParentContent, node);
 
 #ifdef DEBUG_DISPLAY_CONTENTS_MAP
-        printf( "REMOVED!\n");
+      printf( "REMOVED!\n");
 #endif
-#ifdef DEBUG
-        // make sure that there are no more entries for the same content
-        nsStyleContext* context = GetDisplayContentsStyleFor(aContent);
-        NS_ASSERTION(context == nullptr, "Found more entries for aContent after removal");
-#endif
-        ClearAllDisplayContentsIn(aContent);
-        ClearAllUndisplayedContentIn(aContent);
-        return;
-      }
-      node = node->mNext;
+      // make sure that there are no more entries for the same content
+      MOZ_ASSERT(!GetDisplayContentsStyleFor(aContent),
+                 "Found more entries for aContent after removal");
+      ClearAllDisplayContentsIn(aContent);
+      ClearAllUndisplayedContentIn(aContent);
+      return;
     }
   }
 #ifdef DEBUG_DISPLAY_CONTENTS_MAP
@@ -416,14 +418,14 @@ nsFrameManager::ClearAllDisplayContentsIn(nsIContent* aParentContent)
 #endif
 
   if (mDisplayContentsMap) {
-    UndisplayedNode* cur = mDisplayContentsMap->UnlinkNodesFor(aParentContent);
-    while (cur) {
-      UndisplayedNode* next = cur->mNext;
-      cur->mNext = nullptr;
-      ClearAllDisplayContentsIn(cur->mContent);
-      ClearAllUndisplayedContentIn(cur->mContent);
-      delete cur;
-      cur = next;
+    nsAutoPtr<LinkedList<UndisplayedNode>> list =
+      mDisplayContentsMap->UnlinkNodesFor(aParentContent);
+    if (list) {
+      while (UndisplayedNode* node = list->popFirst()) {
+        ClearAllDisplayContentsIn(node->mContent);
+        ClearAllUndisplayedContentIn(node->mContent);
+        delete node;
+      }
     }
   }
 
@@ -654,182 +656,132 @@ nsFrameManager::RestoreFrameState(nsIFrame* aFrame,
 
 //----------------------------------------------------------------------
 
-static PLHashNumber
-HashKey(void* key)
-{
-  return NS_PTR_TO_INT32(key);
-}
-
-static int
-CompareKeys(void* key1, void* key2)
-{
-  return key1 == key2;
-}
-
-//----------------------------------------------------------------------
-
-nsFrameManagerBase::UndisplayedMap::UndisplayedMap(uint32_t aNumBuckets)
+nsFrameManagerBase::UndisplayedMap::UndisplayedMap()
 {
   MOZ_COUNT_CTOR(nsFrameManagerBase::UndisplayedMap);
-  mTable = PL_NewHashTable(aNumBuckets, (PLHashFunction)HashKey,
-                           (PLHashComparator)CompareKeys,
-                           (PLHashComparator)nullptr,
-                           nullptr, nullptr);
-  mLastLookup = nullptr;
 }
 
 nsFrameManagerBase::UndisplayedMap::~UndisplayedMap(void)
 {
   MOZ_COUNT_DTOR(nsFrameManagerBase::UndisplayedMap);
   Clear();
-  PL_HashTableDestroy(mTable);
 }
 
-PLHashEntry**  
-nsFrameManagerBase::UndisplayedMap::GetEntryFor(nsIContent** aParentContent)
+void
+nsFrameManagerBase::UndisplayedMap::Clear()
 {
-  nsIContent* parentContent = *aParentContent;
-
-  if (mLastLookup && (parentContent == (*mLastLookup)->key)) {
-    return mLastLookup;
+  for (auto iter = Iter(); !iter.Done(); iter.Next()) {
+    auto* list = iter.UserData();
+    while (auto* node = list->popFirst()) {
+      delete node;
+    }
+    iter.Remove();
   }
+}
 
+nsIContent*
+nsFrameManagerBase::UndisplayedMap::GetApplicableParent(nsIContent* aParent)
+{
   // In the case of XBL default content, <xbl:children> elements do not get a
   // frame causing a mismatch between the content tree and the frame tree.
   // |GetEntryFor| is sometimes called with the content tree parent (which may
   // be a <xbl:children> element) but the parent in the frame tree would be the
   // insertion parent (parent of the <xbl:children> element). Here the children
   // elements are normalized to the insertion parent to correct for the mismatch.
-  if (parentContent && nsContentUtils::IsContentInsertionPoint(parentContent)) {
-    parentContent = parentContent->GetParent();
-    // Change the caller's pointer for the parent content to be the insertion parent.
-    *aParentContent = parentContent;
+  if (aParent && nsContentUtils::IsContentInsertionPoint(aParent)) {
+    return aParent->GetParent();
   }
 
-  PLHashNumber hashCode = NS_PTR_TO_INT32(parentContent);
-  PLHashEntry** entry = PL_HashTableRawLookup(mTable, hashCode, parentContent);
-  if (*entry) {
-    mLastLookup = entry;
-  }
-  return entry;
+  return aParent;
 }
 
-UndisplayedNode* 
-nsFrameManagerBase::UndisplayedMap::GetFirstNode(nsIContent* aParentContent)
+LinkedList<UndisplayedNode>*
+nsFrameManagerBase::UndisplayedMap::GetListFor(nsIContent** aParent)
 {
-  PLHashEntry** entry = GetEntryFor(&aParentContent);
-  if (*entry) {
-    return (UndisplayedNode*)((*entry)->value);
+  *aParent = GetApplicableParent(*aParent);
+
+  LinkedList<UndisplayedNode>* list;
+  if (Get(*aParent, &list)) {
+    return list;
   }
+
   return nullptr;
 }
 
+LinkedList<UndisplayedNode>*
+nsFrameManagerBase::UndisplayedMap::GetOrCreateListFor(nsIContent** aParent)
+{
+  *aParent = GetApplicableParent(*aParent);
+  return LookupOrAdd(*aParent);
+}
+
+
+UndisplayedNode*
+nsFrameManagerBase::UndisplayedMap::GetFirstNode(nsIContent* aParentContent)
+{
+  auto* list = GetListFor(&aParentContent);
+  return list ? list->getFirst() : nullptr;
+}
+
 void
 nsFrameManagerBase::UndisplayedMap::AppendNodeFor(UndisplayedNode* aNode,
                                                   nsIContent* aParentContent)
 {
-  PLHashEntry** entry = GetEntryFor(&aParentContent);
-  if (*entry) {
-    UndisplayedNode*  node = (UndisplayedNode*)((*entry)->value);
-    while (node->mNext) {
-      if (node->mContent == aNode->mContent) {
-        // We actually need to check this in optimized builds because
-        // there are some callers that do this.  See bug 118014, bug
-        // 136704, etc.
-        NS_NOTREACHED("node in map twice");
-        delete aNode;
-        return;
-      }
-      node = node->mNext;
-    }
-    node->mNext = aNode;
-  }
-  else {
-    PLHashNumber hashCode = NS_PTR_TO_INT32(aParentContent);
-    PL_HashTableRawAdd(mTable, entry, hashCode, aParentContent, aNode);
-    mLastLookup = nullptr; // hashtable may have shifted bucket out from under us
+  LinkedList<UndisplayedNode>* list = GetOrCreateListFor(&aParentContent);
+
+#ifdef DEBUG
+  for (UndisplayedNode* node = list->getFirst(); node; node = node->getNext()) {
+    // NOTE: In the original code there was a work around for this case, I want
+    // to check it still happens before hacking around it the same way.
+    MOZ_ASSERT(node->mContent != aNode->mContent,
+               "Duplicated content in undisplayed list!");
   }
+#endif
+
+  list->insertBack(aNode);
 }
 
-nsresult 
+void
 nsFrameManagerBase::UndisplayedMap::AddNodeFor(nsIContent* aParentContent,
-                                               nsIContent* aChild, 
+                                               nsIContent* aChild,
                                                nsStyleContext* aStyle)
 {
   UndisplayedNode*  node = new UndisplayedNode(aChild, aStyle);
-
   AppendNodeFor(node, aParentContent);
-  return NS_OK;
 }
 
 void
 nsFrameManagerBase::UndisplayedMap::RemoveNodeFor(nsIContent* aParentContent,
                                                   UndisplayedNode* aNode)
 {
-  PLHashEntry** entry = GetEntryFor(&aParentContent);
-  NS_ASSERTION(*entry, "content not in map");
-  if (*entry) {
-    if ((UndisplayedNode*)((*entry)->value) == aNode) {  // first node
-      if (aNode->mNext) {
-        (*entry)->value = aNode->mNext;
-        aNode->mNext = nullptr;
-      }
-      else {
-        PL_HashTableRawRemove(mTable, entry, *entry);
-        mLastLookup = nullptr; // hashtable may have shifted bucket out from under us
-      }
-    }
-    else {
-      UndisplayedNode*  node = (UndisplayedNode*)((*entry)->value);
-      while (node->mNext) {
-        if (node->mNext == aNode) {
-          node->mNext = aNode->mNext;
-          aNode->mNext = nullptr;
-          break;
-        }
-        node = node->mNext;
-      }
-    }
-  }
+#ifdef DEBUG
+  auto list = GetListFor(&aParentContent);
+  MOZ_ASSERT(list, "content not in map");
+  aNode->removeFrom(*list);
+#else
+  aNode->remove();
+#endif
   delete aNode;
 }
 
 
-UndisplayedNode*
+nsAutoPtr<LinkedList<UndisplayedNode>>
 nsFrameManagerBase::UndisplayedMap::UnlinkNodesFor(nsIContent* aParentContent)
 {
-  PLHashEntry** entry = GetEntryFor(&aParentContent);
-  NS_ASSERTION(entry, "content not in map");
-  if (*entry) {
-    UndisplayedNode* node = (UndisplayedNode*)((*entry)->value);
-    NS_ASSERTION(node, "null node for non-null entry in UndisplayedMap");
-    PL_HashTableRawRemove(mTable, entry, *entry);
-    mLastLookup = nullptr; // hashtable may have shifted bucket out from under us
-    return node;
-  }
-  return nullptr;
+  nsAutoPtr<LinkedList<UndisplayedNode>> list;
+  RemoveAndForget(GetApplicableParent(aParentContent), list);
+  return list;
 }
 
 void
 nsFrameManagerBase::UndisplayedMap::RemoveNodesFor(nsIContent* aParentContent)
 {
-  delete UnlinkNodesFor(aParentContent);
-}
-
-static int
-RemoveUndisplayedEntry(PLHashEntry* he, int i, void* arg)
-{
-  UndisplayedNode*  node = (UndisplayedNode*)(he->value);
-  delete node;
-  // Remove and free this entry and continue enumerating
-  return HT_ENUMERATE_REMOVE | HT_ENUMERATE_NEXT;
-}
-
-void
-nsFrameManagerBase::UndisplayedMap::Clear(void)
-{
-  mLastLookup = nullptr;
-  PL_HashTableEnumerateEntries(mTable, RemoveUndisplayedEntry, 0);
+  nsAutoPtr<LinkedList<UndisplayedNode>> list = UnlinkNodesFor(aParentContent);
+  if (list) {
+    while (auto* node = list->popFirst()) {
+      delete node;
+    }
+  }
 }
 
 uint32_t nsFrameManagerBase::sGlobalGenerationNumber;
diff --git a/layout/base/nsFrameManager.h b/layout/base/nsFrameManager.h
index 1b9148314f..bca4a581ad 100644
--- a/layout/base/nsFrameManager.h
+++ b/layout/base/nsFrameManager.h
@@ -33,32 +33,19 @@ namespace mozilla {
  * Node in a linked list, containing the style for an element that
  * does not have a frame but whose parent does have a frame.
  */
-struct UndisplayedNode {
+struct UndisplayedNode : public LinkedListElement<UndisplayedNode>
+{
   UndisplayedNode(nsIContent* aContent, nsStyleContext* aStyle)
-    : mContent(aContent),
-      mStyle(aStyle),
-      mNext(nullptr)
+    : mContent(aContent)
+    , mStyle(aStyle)
   {
     MOZ_COUNT_CTOR(mozilla::UndisplayedNode);
   }
 
-  ~UndisplayedNode()
-  {
-    MOZ_COUNT_DTOR(mozilla::UndisplayedNode);
-
-    // Delete mNext iteratively to avoid blowing up the stack (bug 460461).
-    UndisplayedNode* cur = mNext;
-    while (cur) {
-      UndisplayedNode* next = cur->mNext;
-      cur->mNext = nullptr;
-      delete cur;
-      cur = next;
-    }
-  }
+  ~UndisplayedNode() { MOZ_COUNT_DTOR(mozilla::UndisplayedNode); }
 
-  nsCOMPtr<nsIContent>      mContent;
-  RefPtr<nsStyleContext>  mStyle;
-  UndisplayedNode*          mNext;
+  nsCOMPtr<nsIContent> mContent;
+  RefPtr<nsStyleContext> mStyle;
 };
 
 } // namespace mozilla
diff --git a/layout/base/nsIPresShell.h b/layout/base/nsIPresShell.h
index 865f5534c6..f89639b3e1 100644
--- a/layout/base/nsIPresShell.h
+++ b/layout/base/nsIPresShell.h
@@ -977,7 +977,7 @@ public:
   /**
    * Reconstruct frames for all elements in the document
    */
-  virtual nsresult ReconstructFrames() = 0;
+  virtual void ReconstructFrames() = 0;
 
   /**
    * Notify that a content node's state has changed
diff --git a/layout/base/nsPresShell.cpp b/layout/base/nsPresShell.cpp
index 264b52b18d..b190622c7c 100644
--- a/layout/base/nsPresShell.cpp
+++ b/layout/base/nsPresShell.cpp
@@ -4444,14 +4444,14 @@ PresShell::NotifyCounterStylesAreDirty()
   mFrameConstructor->EndUpdate();
 }
 
-nsresult
-PresShell::ReconstructFrames(void)
+void
+PresShell::ReconstructFrames()
 {
   NS_PRECONDITION(!mFrameConstructor->GetRootFrame() || mDidInitialize,
                   "Must not have root frame before initial reflow");
   if (!mDidInitialize || mIsDestroying) {
     // Nothing to do here
-    return NS_OK;
+    return;
   }
 
   nsCOMPtr<nsIPresShell> kungFuDeathGrip(this);
@@ -4461,16 +4461,14 @@ PresShell::ReconstructFrames(void)
   mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
 
   if (mIsDestroying) {
-    return NS_OK;
+    return;
   }
 
   nsAutoCauseReflowNotifier crNotifier(this);
   mFrameConstructor->BeginUpdate();
-  nsresult rv = mFrameConstructor->ReconstructDocElementHierarchy();
+  mFrameConstructor->ReconstructDocElementHierarchy();
   VERIFY_STYLE_TREE;
   mFrameConstructor->EndUpdate();
-
-  return rv;
 }
 
 void
diff --git a/layout/base/nsPresShell.h b/layout/base/nsPresShell.h
index f20370d73a..f276273fa3 100644
--- a/layout/base/nsPresShell.h
+++ b/layout/base/nsPresShell.h
@@ -200,7 +200,7 @@ public:
 
   virtual void NotifyCounterStylesAreDirty() override;
 
-  virtual nsresult ReconstructFrames(void) override;
+  virtual void ReconstructFrames(void) override;
   virtual void Freeze() override;
   virtual void Thaw() override;
   virtual void FireOrClearDelayedEvents(bool aFireEvents) override;