--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -3215,23 +3215,17 @@ nsCSSFrameConstructor::ConstructTextFram
 {
   NS_PRECONDITION(aData, "Must have frame construction data");
 
   nsIFrame* newFrame = (*aData->mFunc.mCreationFunc)(mPresShell, aStyleContext);
 
   if (MOZ_UNLIKELY(!newFrame))
     return NS_ERROR_OUT_OF_MEMORY;
 
-  nsresult rv = InitAndRestoreFrame(aState, aContent, aParentFrame,
-                                    nullptr, newFrame);
-
-  if (NS_FAILED(rv)) {
-    newFrame->Destroy();
-    return rv;
-  }
+  InitAndRestoreFrame(aState, aContent, aParentFrame, nullptr, newFrame);
 
   // We never need to create a view for a text frame.
 
   if (newFrame->IsGeneratedContentFrame()) {
     nsAutoPtr<nsGenConInitializer> initializer;
     initializer =
       static_cast<nsGenConInitializer*>(
         aContent->UnsetProperty(nsGkAtoms::genConInitializerProperty));
@@ -3245,17 +3239,17 @@ nsCSSFrameConstructor::ConstructTextFram
   }
   
   // Add the newly constructed frame to the flow
   aFrameItems.AddChild(newFrame);
 
   if (!aState.mCreatingExtraFrames)
     aContent->SetPrimaryFrame(newFrame);
   
-  return rv;
+  return NS_OK;
 }
 
 /* static */
 const nsCSSFrameConstructor::FrameConstructionData*
 nsCSSFrameConstructor::FindDataByInt(int32_t aInt,
                                      Element* aElement,
                                      nsStyleContext* aStyleContext,
                                      const FrameConstructionDataByInt* aDataPtr,
@@ -3620,19 +3614,17 @@ nsCSSFrameConstructor::ConstructFrameFro
 
     // Must init frameToAddToList to null, since it's inout
     nsIFrame* frameToAddToList = nullptr;
     if ((bits & FCDATA_MAY_NEED_SCROLLFRAME) &&
         display->IsScrollableOverflow()) {
       BuildScrollFrame(aState, content, styleContext, newFrame,
                        geometricParent, frameToAddToList);
     } else {
-      rv = InitAndRestoreFrame(aState, content, geometricParent, nullptr,
-                               newFrame);
-      NS_ASSERTION(NS_SUCCEEDED(rv), "InitAndRestoreFrame failed");
+      InitAndRestoreFrame(aState, content, geometricParent, nullptr, newFrame);
       // See whether we need to create a view
       nsContainerFrame::CreateViewForFrame(newFrame, false);
       frameToAddToList = newFrame;
     }
 
     // Use frameToAddToList as the primary frame.  In the non-scrollframe case
     // they're equal, but in the scrollframe case newFrame is the scrolled
     // frame, while frameToAddToList is the scrollframe (and should be the
@@ -3651,22 +3643,17 @@ nsCSSFrameConstructor::ConstructFrameFro
                                                          styleContext);
       nsIFrame* blockFrame =
         NS_NewBlockFormattingContext(mPresShell, blockContext);
       if (MOZ_UNLIKELY(!blockFrame)) {
         primaryFrame->Destroy();
         return NS_ERROR_OUT_OF_MEMORY;
       }
 
-      rv = InitAndRestoreFrame(aState, content, newFrame, nullptr, blockFrame);
-      if (NS_FAILED(rv)) {
-        blockFrame->Destroy();
-        primaryFrame->Destroy();
-        return rv;
-      }
+      InitAndRestoreFrame(aState, content, newFrame, nullptr, blockFrame);
 
       SetInitialSingleChild(newFrame, blockFrame);
 
       // Now figure out whether newFrame or blockFrame should be the
       // absolute container.  It should be the latter if it's
       // positioned, otherwise the former.
       const nsStyleDisplay* blockDisplay = blockContext->StyleDisplay();
       if (blockDisplay->IsPositioned(blockFrame)) {
@@ -4495,46 +4482,42 @@ nsCSSFrameConstructor::ConstructNonScrol
   return ConstructBlock(aState, aDisplay, aItem.mContent,
                         aState.GetGeometricParent(aDisplay, aParentFrame),
                         aParentFrame, styleContext, aNewFrame,
                         aFrameItems, aDisplay->IsPositioned(*aNewFrame),
                         aItem.mPendingBinding);
 }
 
 
-nsresult 
+void
 nsCSSFrameConstructor::InitAndRestoreFrame(const nsFrameConstructorState& aState,
                                            nsIContent*              aContent,
                                            nsIFrame*                aParentFrame,
                                            nsIFrame*                aPrevInFlow,
                                            nsIFrame*                aNewFrame,
                                            bool                     aAllowCounters)
 {
   NS_PRECONDITION(mUpdateCount != 0,
                   "Should be in an update while creating frames");
   
-  NS_ASSERTION(aNewFrame, "Null frame cannot be initialized");
-  if (!aNewFrame)
-    return NS_ERROR_NULL_POINTER;
+  MOZ_ASSERT(aNewFrame, "Null frame cannot be initialized");
 
   // Initialize the frame
   aNewFrame->Init(aContent, aParentFrame, aPrevInFlow);
   aNewFrame->AddStateBits(aState.mAdditionalStateBits);
 
   if (aState.mFrameState) {
     // Restore frame state for just the newly created frame.
     RestoreFrameStateFor(aNewFrame, aState.mFrameState);
   }
 
   if (aAllowCounters && !aPrevInFlow &&
       mCounterManager.AddCounterResetsAndIncrements(aNewFrame)) {
     CountersDirty();
   }
-
-  return NS_OK;
 }
 
 already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::ResolveStyleContext(nsIFrame*         aParentFrame,
                                            nsIContent*       aContent,
                                            nsFrameConstructorState* aState)
 {
   nsStyleContext* parentStyleContext = nullptr;
@@ -10178,18 +10161,18 @@ nsCSSFrameConstructor::WrapFramesInFirst
                                        nsCSSPseudoElements::firstLine)->
         StyleContext();
     nsRefPtr<nsStyleContext> firstLineStyle = GetFirstLineStyle(aBlockContent,
                                                                 parentStyle);
 
     aLineFrame = NS_NewFirstLineFrame(mPresShell, firstLineStyle);
 
     // Initialize the line frame
-    rv = InitAndRestoreFrame(aState, aBlockContent, aBlockFrame, nullptr,
-                             aLineFrame);
+    InitAndRestoreFrame(aState, aBlockContent, aBlockFrame, nullptr,
+                        aLineFrame);
 
     // The lineFrame will be the block's first child; the rest of the
     // frame list (after lastInlineFrame) will be the second and
     // subsequent children; insert lineFrame into aFrameItems.
     aFrameItems.InsertFrame(nullptr, nullptr, aLineFrame);
 
     NS_ASSERTION(aLineFrame->StyleContext() == firstLineStyle,
                  "Bogus style context on line frame");
@@ -10302,18 +10285,18 @@ nsCSSFrameConstructor::InsertFirstLineFr
           nsStyleContext* parentStyle =
             nsFrame::CorrectStyleParentFrame(aBlockFrame,
                                              nsCSSPseudoElements::firstLine)->
               StyleContext();
           nsRefPtr<nsStyleContext> firstLineStyle =
             GetFirstLineStyle(aContent, parentStyle);
 
           // Initialize the line frame
-          rv = InitAndRestoreFrame(aState, aContent, aBlockFrame,
-                                   nullptr, lineFrame);
+          InitAndRestoreFrame(aState, aContent, aBlockFrame,
+                              nullptr, lineFrame);
 
           // Make sure the caller inserts the lineFrame into the
           // blocks list of children.
           aFrameItems.childList = lineFrame;
           aFrameItems.lastChild = lineFrame;
 
           // Give the inline frames to the lineFrame <b>after</b>
           // reparenting them

--- a/layout/base/nsCSSFrameConstructor.h
+++ b/layout/base/nsCSSFrameConstructor.h
@@ -396,22 +396,22 @@ private:
   /* aMinHint is the minimal change that should be made to the element */
   // XXXbz do we really need the aPrimaryFrame argument here?
   void RestyleElement(Element* aElement,
                       nsIFrame*       aPrimaryFrame,
                       nsChangeHint    aMinHint,
                       RestyleTracker& aRestyleTracker,
                       bool            aRestyleDescendants);
 
-  nsresult InitAndRestoreFrame (const nsFrameConstructorState& aState,
-                                nsIContent*                    aContent,
-                                nsIFrame*                      aParentFrame,
-                                nsIFrame*                      aPrevInFlow,
-                                nsIFrame*                      aNewFrame,
-                                bool                           aAllowCounters = true);
+  void InitAndRestoreFrame (const nsFrameConstructorState& aState,
+                            nsIContent*                    aContent,
+                            nsIFrame*                      aParentFrame,
+                            nsIFrame*                      aPrevInFlow,
+                            nsIFrame*                      aNewFrame,
+                            bool                           aAllowCounters = true);
 
   // aState can be null if not available; it's used as an optimization.
   // XXXbz IsValidSibling is the only caller that doesn't pass a state here!
   already_AddRefed<nsStyleContext>
   ResolveStyleContext(nsIFrame*         aParentFrame,
                       nsIContent*       aContent,
                       nsFrameConstructorState* aState);
   already_AddRefed<nsStyleContext>