diff --git a/layout/forms/nsFileControlFrame.cpp b/layout/forms/nsFileControlFrame.cpp
index b2ce5df1ff56..7c2418e0ac36 100644
--- a/layout/forms/nsFileControlFrame.cpp
+++ b/layout/forms/nsFileControlFrame.cpp
@@ -43,9 +43,9 @@ nsFileControlFrame::nsFileControlFrame(nsStyleContext* aContext)
 
 
 void
-nsFileControlFrame::Init(nsIContent* aContent,
-                         nsIFrame*   aParent,
-                         nsIFrame*   aPrevInFlow)
+nsFileControlFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   nsBlockFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/forms/nsFileControlFrame.h b/layout/forms/nsFileControlFrame.h
index 7b7bd7b254d4..844dc8b82b4f 100644
--- a/layout/forms/nsFileControlFrame.h
+++ b/layout/forms/nsFileControlFrame.h
@@ -23,9 +23,9 @@ class nsFileControlFrame : public nsBlockFrame,
 public:
   nsFileControlFrame(nsStyleContext* aContext);
 
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
diff --git a/layout/forms/nsGfxButtonControlFrame.cpp b/layout/forms/nsGfxButtonControlFrame.cpp
index c5a2252e14c5..b075f71998a4 100644
--- a/layout/forms/nsGfxButtonControlFrame.cpp
+++ b/layout/forms/nsGfxButtonControlFrame.cpp
@@ -83,7 +83,7 @@ nsGfxButtonControlFrame::CreateFrameFor(nsIContent*      aContent)
   nsIFrame * newFrame = nullptr;
 
   if (aContent == mTextContent) {
-    nsIFrame * parentFrame = mFrames.FirstChild();
+    nsContainerFrame* parentFrame = do_QueryFrame(mFrames.FirstChild());
 
     nsPresContext* presContext = PresContext();
     nsRefPtr<nsStyleContext> textStyleContext;
diff --git a/layout/forms/nsHTMLButtonControlFrame.cpp b/layout/forms/nsHTMLButtonControlFrame.cpp
index 00cd441e2046..ecdc9f8ab230 100644
--- a/layout/forms/nsHTMLButtonControlFrame.cpp
+++ b/layout/forms/nsHTMLButtonControlFrame.cpp
@@ -44,10 +44,9 @@ nsHTMLButtonControlFrame::DestroyFrom(nsIFrame* aDestructRoot)
 }
 
 void
-nsHTMLButtonControlFrame::Init(
-              nsIContent*      aContent,
-              nsIFrame*        aParent,
-              nsIFrame*        aPrevInFlow)
+nsHTMLButtonControlFrame::Init(nsIContent*       aContent,
+                               nsContainerFrame* aParent,
+                               nsIFrame*         aPrevInFlow)
 {
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
   mRenderer.SetFrame(this, PresContext());
diff --git a/layout/forms/nsHTMLButtonControlFrame.h b/layout/forms/nsHTMLButtonControlFrame.h
index 818c0b7b2010..eaf6a14b0222 100644
--- a/layout/forms/nsHTMLButtonControlFrame.h
+++ b/layout/forms/nsHTMLButtonControlFrame.h
@@ -43,9 +43,9 @@ public:
                                mozilla::WidgetGUIEvent* aEvent,
                                nsEventStatus* aEventStatus) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsStyleContext* GetAdditionalStyleContext(int32_t aIndex) const MOZ_OVERRIDE;
   virtual void SetAdditionalStyleContext(int32_t aIndex, 
diff --git a/layout/forms/nsImageControlFrame.cpp b/layout/forms/nsImageControlFrame.cpp
index 05ed1a49c9da..57c1ac44a94d 100644
--- a/layout/forms/nsImageControlFrame.cpp
+++ b/layout/forms/nsImageControlFrame.cpp
@@ -22,9 +22,9 @@ public:
   ~nsImageControlFrame();
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
@@ -86,9 +86,9 @@ NS_NewImageControlFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 NS_IMPL_FRAMEARENA_HELPERS(nsImageControlFrame)
 
 void
-nsImageControlFrame::Init(nsIContent*      aContent,
-                          nsIFrame*        aParent,
-                          nsIFrame*        aPrevInFlow)
+nsImageControlFrame::Init(nsIContent*       aContent,
+                          nsContainerFrame* aParent,
+                          nsIFrame*         aPrevInFlow)
 {
   nsImageControlFrameSuper::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/forms/nsListControlFrame.cpp b/layout/forms/nsListControlFrame.cpp
index 02682cffc432..b60daa3f57a0 100644
--- a/layout/forms/nsListControlFrame.cpp
+++ b/layout/forms/nsListControlFrame.cpp
@@ -923,9 +923,9 @@ nsListControlFrame::SetInitialChildList(ChildListID    aListID,
 
 //---------------------------------------------------------
 void
-nsListControlFrame::Init(nsIContent*     aContent,
-                         nsIFrame*       aParent,
-                         nsIFrame*       aPrevInFlow)
+nsListControlFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   nsHTMLScrollFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/forms/nsListControlFrame.h b/layout/forms/nsListControlFrame.h
index 301773d827f0..d2647d38b91b 100644
--- a/layout/forms/nsListControlFrame.h
+++ b/layout/forms/nsListControlFrame.h
@@ -74,9 +74,9 @@ public:
                       const nsHTMLReflowState& aReflowState,
                       nsReflowStatus&          aStatus) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DidReflow(nsPresContext*            aPresContext, 
                          const nsHTMLReflowState*  aReflowState, 
diff --git a/layout/forms/nsRangeFrame.cpp b/layout/forms/nsRangeFrame.cpp
index 74c15cf15abf..91ca7d5aec35 100644
--- a/layout/forms/nsRangeFrame.cpp
+++ b/layout/forms/nsRangeFrame.cpp
@@ -59,9 +59,9 @@ NS_QUERYFRAME_HEAD(nsRangeFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 
 void
-nsRangeFrame::Init(nsIContent* aContent,
-                   nsIFrame*   aParent,
-                   nsIFrame*   aPrevInFlow)
+nsRangeFrame::Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow)
 {
   // B2G's AsyncPanZoomController::ReceiveInputEvent handles touch events
   // without checking whether the out-of-process document that it controls
diff --git a/layout/forms/nsRangeFrame.h b/layout/forms/nsRangeFrame.h
index 5a083cfeaae9..5fce75e902a7 100644
--- a/layout/forms/nsRangeFrame.h
+++ b/layout/forms/nsRangeFrame.h
@@ -35,9 +35,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
   // nsIFrame overrides
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/generic/nsBlockFrame.cpp b/layout/generic/nsBlockFrame.cpp
index dd302d440223..2a4a7060b3fd 100644
--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -6419,9 +6419,9 @@ nsBlockFrame::ChildIsDirty(nsIFrame* aChild)
 }
 
 void
-nsBlockFrame::Init(nsIContent*      aContent,
-                   nsIFrame*        aParent,
-                   nsIFrame*        aPrevInFlow)
+nsBlockFrame::Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow)
 {
   if (aPrevInFlow) {
     // Copy over the inherited block frame bits from the prev-in-flow.
diff --git a/layout/generic/nsBlockFrame.h b/layout/generic/nsBlockFrame.h
index 9da5baf10017..5e45b8f6dff4 100644
--- a/layout/generic/nsBlockFrame.h
+++ b/layout/generic/nsBlockFrame.h
@@ -107,9 +107,9 @@ public:
   NS_DECL_QUERYFRAME
 
   // nsIFrame
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual nsresult SetInitialChildList(ChildListID     aListID,
                                        nsFrameList&    aChildList) MOZ_OVERRIDE;
   virtual nsresult  AppendFrames(ChildListID     aListID,
diff --git a/layout/generic/nsContainerFrame.cpp b/layout/generic/nsContainerFrame.cpp
index 6dd6a290628d..a19580630ebe 100644
--- a/layout/generic/nsContainerFrame.cpp
+++ b/layout/generic/nsContainerFrame.cpp
@@ -53,9 +53,9 @@ NS_QUERYFRAME_HEAD(nsContainerFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsSplittableFrame)
 
 void
-nsContainerFrame::Init(nsIContent* aContent,
-                       nsIFrame*   aParent,
-                       nsIFrame*   aPrevInFlow)
+nsContainerFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   nsSplittableFrame::Init(aContent, aParent, aPrevInFlow);
   if (aPrevInFlow) {
diff --git a/layout/generic/nsContainerFrame.h b/layout/generic/nsContainerFrame.h
index a37c021b60c7..9d1a8ab79dc8 100644
--- a/layout/generic/nsContainerFrame.h
+++ b/layout/generic/nsContainerFrame.h
@@ -49,9 +49,9 @@ public:
   NS_DECL_QUERYFRAME
 
   // nsIFrame overrides
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual nsresult SetInitialChildList(ChildListID  aListID,
                                        nsFrameList& aChildList) MOZ_OVERRIDE;
   virtual nsresult AppendFrames(ChildListID  aListID,
diff --git a/layout/generic/nsFirstLetterFrame.cpp b/layout/generic/nsFirstLetterFrame.cpp
index f524a6bcbdf8..88d67f4602f6 100644
--- a/layout/generic/nsFirstLetterFrame.cpp
+++ b/layout/generic/nsFirstLetterFrame.cpp
@@ -56,9 +56,9 @@ nsFirstLetterFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 }
 
 void
-nsFirstLetterFrame::Init(nsIContent*      aContent,
-                         nsIFrame*        aParent,
-                         nsIFrame*        aPrevInFlow)
+nsFirstLetterFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   nsRefPtr<nsStyleContext> newSC;
   if (aPrevInFlow) {
diff --git a/layout/generic/nsFirstLetterFrame.h b/layout/generic/nsFirstLetterFrame.h
index 68a3730249ab..7092b302dc21 100644
--- a/layout/generic/nsFirstLetterFrame.h
+++ b/layout/generic/nsFirstLetterFrame.h
@@ -23,9 +23,9 @@ public:
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual nsresult SetInitialChildList(ChildListID     aListID,
                                        nsFrameList&    aChildList) MOZ_OVERRIDE;
 #ifdef DEBUG_FRAME_DUMP
diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index d3d0a23f251e..954bde217fad 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -457,9 +457,9 @@ IsFontSizeInflationContainer(nsIFrame* aFrame,
 }
 
 void
-nsFrame::Init(nsIContent*      aContent,
-              nsIFrame*        aParent,
-              nsIFrame*        aPrevInFlow)
+nsFrame::Init(nsIContent*       aContent,
+              nsContainerFrame* aParent,
+              nsIFrame*         aPrevInFlow)
 {
   NS_PRECONDITION(!mContent, "Double-initing a frame?");
   NS_ASSERTION(IsFrameOfType(eDEBUGAllFrames) &&
diff --git a/layout/generic/nsFrame.h b/layout/generic/nsFrame.h
index a12c4ab71a25..949cd2522f23 100644
--- a/layout/generic/nsFrame.h
+++ b/layout/generic/nsFrame.h
@@ -141,9 +141,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
   // nsIFrame
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual nsresult  SetInitialChildList(ChildListID  aListID,
                                         nsFrameList& aChildList) MOZ_OVERRIDE;
   virtual nsresult  AppendFrames(ChildListID     aListID,
diff --git a/layout/generic/nsFrameSetFrame.cpp b/layout/generic/nsFrameSetFrame.cpp
index 65176358cf86..d6665a35da2b 100644
--- a/layout/generic/nsFrameSetFrame.cpp
+++ b/layout/generic/nsFrameSetFrame.cpp
@@ -241,9 +241,9 @@ nsHTMLFramesetFrame::FrameResizePrefCallback(const char* aPref, void* aClosure)
 }
 
 void
-nsHTMLFramesetFrame::Init(nsIContent*      aContent,
-                          nsIFrame*        aParent,
-                          nsIFrame*        aPrevInFlow)
+nsHTMLFramesetFrame::Init(nsIContent*       aContent,
+                          nsContainerFrame* aParent,
+                          nsIFrame*         aPrevInFlow)
 {
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
   // find the highest ancestor that is a frameset
diff --git a/layout/generic/nsFrameSetFrame.h b/layout/generic/nsFrameSetFrame.h
index 414092d74e3e..ec0c763c304c 100644
--- a/layout/generic/nsFrameSetFrame.h
+++ b/layout/generic/nsFrameSetFrame.h
@@ -72,9 +72,9 @@ public:
 
   virtual ~nsHTMLFramesetFrame();
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult SetInitialChildList(ChildListID  aListID,
                                        nsFrameList& aChildList) MOZ_OVERRIDE;
diff --git a/layout/generic/nsHTMLCanvasFrame.cpp b/layout/generic/nsHTMLCanvasFrame.cpp
index 883abe3676bf..4b6137eaaa50 100644
--- a/layout/generic/nsHTMLCanvasFrame.cpp
+++ b/layout/generic/nsHTMLCanvasFrame.cpp
@@ -92,9 +92,9 @@ NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 NS_IMPL_FRAMEARENA_HELPERS(nsHTMLCanvasFrame)
 
 void
-nsHTMLCanvasFrame::Init(nsIContent* aContent,
-                        nsIFrame*   aParent,
-                        nsIFrame*   aPrevInFlow)
+nsHTMLCanvasFrame::Init(nsIContent*       aContent,
+                        nsContainerFrame* aParent,
+                        nsIFrame*         aPrevInFlow)
 {
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/generic/nsHTMLCanvasFrame.h b/layout/generic/nsHTMLCanvasFrame.h
index cf2dac7d8285..c5bb34f93a1a 100644
--- a/layout/generic/nsHTMLCanvasFrame.h
+++ b/layout/generic/nsHTMLCanvasFrame.h
@@ -38,9 +38,9 @@ public:
 
   nsHTMLCanvasFrame(nsStyleContext* aContext) : nsContainerFrame(aContext) {}
 
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
diff --git a/layout/generic/nsIFrame.h b/layout/generic/nsIFrame.h
index 69f88ab36d63..b81905c664b2 100644
--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -430,9 +430,9 @@ public:
    * @param   aParent the parent frame
    * @param   aPrevInFlow the prev-in-flow frame
    */
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) = 0;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) = 0;
 
   /**
    * Destroys this frame and each of its child frames (recursively calls
diff --git a/layout/generic/nsImageFrame.cpp b/layout/generic/nsImageFrame.cpp
index 592860292422..31e8d0739743 100644
--- a/layout/generic/nsImageFrame.cpp
+++ b/layout/generic/nsImageFrame.cpp
@@ -219,9 +219,9 @@ nsImageFrame::DestroyFrom(nsIFrame* aDestructRoot)
 
 
 void
-nsImageFrame::Init(nsIContent*      aContent,
-                   nsIFrame*        aParent,
-                   nsIFrame*        aPrevInFlow)
+nsImageFrame::Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow)
 {
   nsSplittableFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/generic/nsImageFrame.h b/layout/generic/nsImageFrame.h
index c8b531a69702..14f12b416ad6 100644
--- a/layout/generic/nsImageFrame.h
+++ b/layout/generic/nsImageFrame.h
@@ -71,9 +71,9 @@ public:
   NS_DECL_QUERYFRAME
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
diff --git a/layout/generic/nsInlineFrame.cpp b/layout/generic/nsInlineFrame.cpp
index dee5be70e716..21efe7b1ebd9 100644
--- a/layout/generic/nsInlineFrame.cpp
+++ b/layout/generic/nsInlineFrame.cpp
@@ -964,8 +964,9 @@ NS_NewFirstLineFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 NS_IMPL_FRAMEARENA_HELPERS(nsFirstLineFrame)
 
 void
-nsFirstLineFrame::Init(nsIContent* aContent, nsIFrame* aParent,
-                       nsIFrame* aPrevInFlow)
+nsFirstLineFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   nsInlineFrame::Init(aContent, aParent, aPrevInFlow);
   if (!aPrevInFlow) {
diff --git a/layout/generic/nsInlineFrame.h b/layout/generic/nsInlineFrame.h
index b064fe8b7b2f..86bce8532013 100644
--- a/layout/generic/nsInlineFrame.h
+++ b/layout/generic/nsInlineFrame.h
@@ -200,8 +200,9 @@ public:
                       const nsHTMLReflowState& aReflowState,
                       nsReflowStatus& aStatus) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent* aContent, nsIFrame* aParent,
-                    nsIFrame* aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void PullOverflowsFromPrevInFlow() MOZ_OVERRIDE;
   virtual bool DrainSelfOverflowList() MOZ_OVERRIDE;
 
diff --git a/layout/generic/nsObjectFrame.cpp b/layout/generic/nsObjectFrame.cpp
index 37a9043a47d5..a75fe8da7100 100644
--- a/layout/generic/nsObjectFrame.cpp
+++ b/layout/generic/nsObjectFrame.cpp
@@ -225,9 +225,9 @@ NS_IMETHODIMP nsObjectFrame::GetPluginPort(HWND *aPort)
 #endif
 
 void
-nsObjectFrame::Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow)
+nsObjectFrame::Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow)
 {
   PR_LOG(GetObjectFrameLog(), PR_LOG_DEBUG,
          ("Initializing nsObjectFrame %p for content %p\n", this, aContent));
diff --git a/layout/generic/nsObjectFrame.h b/layout/generic/nsObjectFrame.h
index 39f68b7d1bae..b863f2fd3fbb 100644
--- a/layout/generic/nsObjectFrame.h
+++ b/layout/generic/nsObjectFrame.h
@@ -58,9 +58,9 @@ public:
   NS_DECL_QUERYFRAME
   NS_DECL_QUERYFRAME_TARGET(nsObjectFrame)
 
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame* aParent,
-                    nsIFrame* aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual nscoord GetMinWidth(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
   virtual nscoord GetPrefWidth(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
   virtual void Reflow(nsPresContext* aPresContext,
diff --git a/layout/generic/nsSplittableFrame.cpp b/layout/generic/nsSplittableFrame.cpp
index 114d021a0ce4..42c4b2cca520 100644
--- a/layout/generic/nsSplittableFrame.cpp
+++ b/layout/generic/nsSplittableFrame.cpp
@@ -15,9 +15,9 @@
 NS_IMPL_FRAMEARENA_HELPERS(nsSplittableFrame)
 
 void
-nsSplittableFrame::Init(nsIContent*      aContent,
-                        nsIFrame*        aParent,
-                        nsIFrame*        aPrevInFlow)
+nsSplittableFrame::Init(nsIContent*       aContent,
+                        nsContainerFrame* aParent,
+                        nsIFrame*         aPrevInFlow)
 {
   nsFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/generic/nsSplittableFrame.h b/layout/generic/nsSplittableFrame.h
index 941251e164ae..7c77c8389877 100644
--- a/layout/generic/nsSplittableFrame.h
+++ b/layout/generic/nsSplittableFrame.h
@@ -20,9 +20,9 @@ class nsSplittableFrame : public nsFrame
 public:
   NS_DECL_FRAMEARENA_HELPERS
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   
   virtual nsSplittableType GetSplittableType() const MOZ_OVERRIDE;
 
diff --git a/layout/generic/nsSubDocumentFrame.cpp b/layout/generic/nsSubDocumentFrame.cpp
index 86af69deb9c5..8add1bc5a096 100644
--- a/layout/generic/nsSubDocumentFrame.cpp
+++ b/layout/generic/nsSubDocumentFrame.cpp
@@ -95,9 +95,9 @@ static void
 EndSwapDocShellsForViews(nsView* aView);
 
 void
-nsSubDocumentFrame::Init(nsIContent*     aContent,
-                         nsIFrame*       aParent,
-                         nsIFrame*       aPrevInFlow)
+nsSubDocumentFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   // determine if we are a <frame> or <iframe>
   if (aContent) {
diff --git a/layout/generic/nsSubDocumentFrame.h b/layout/generic/nsSubDocumentFrame.h
index f6196ddd7bd9..ef586f4dea68 100644
--- a/layout/generic/nsSubDocumentFrame.h
+++ b/layout/generic/nsSubDocumentFrame.h
@@ -39,9 +39,9 @@ public:
       ~(nsIFrame::eReplaced | nsIFrame::eReplacedContainsBlock));
   }
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/generic/nsTextFrame.cpp b/layout/generic/nsTextFrame.cpp
index 95b49fa857b5..179405f90346 100644
--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -3850,9 +3850,9 @@ nsTextFrame::AccessibleType()
 
 //-----------------------------------------------------------------------------
 void
-nsTextFrame::Init(nsIContent*      aContent,
-                  nsIFrame*        aParent,
-                  nsIFrame*        aPrevInFlow)
+nsTextFrame::Init(nsIContent*       aContent,
+                  nsContainerFrame* aParent,
+                  nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(!aPrevInFlow, "Can't be a continuation!");
   NS_PRECONDITION(aContent->IsNodeOfType(nsINode::eTEXT),
@@ -3912,9 +3912,9 @@ public:
 
   friend nsIFrame* NS_NewContinuingTextFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
@@ -3964,9 +3964,9 @@ protected:
 };
 
 void
-nsContinuingTextFrame::Init(nsIContent* aContent,
-                            nsIFrame*   aParent,
-                            nsIFrame*   aPrevInFlow)
+nsContinuingTextFrame::Init(nsIContent*       aContent,
+                            nsContainerFrame* aParent,
+                            nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aPrevInFlow, "Must be a continuation!");
   // NOTE: bypassing nsTextFrame::Init!!!
diff --git a/layout/generic/nsTextFrame.h b/layout/generic/nsTextFrame.h
index 6e82664aff40..1cc62c5ad651 100644
--- a/layout/generic/nsTextFrame.h
+++ b/layout/generic/nsTextFrame.h
@@ -51,9 +51,9 @@ public:
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
   
diff --git a/layout/generic/nsViewportFrame.cpp b/layout/generic/nsViewportFrame.cpp
index 75853e4ac504..b108cb5d8c2c 100644
--- a/layout/generic/nsViewportFrame.cpp
+++ b/layout/generic/nsViewportFrame.cpp
@@ -29,9 +29,9 @@ NS_QUERYFRAME_HEAD(ViewportFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 
 void
-ViewportFrame::Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow)
+ViewportFrame::Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow)
 {
   Super::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/generic/nsViewportFrame.h b/layout/generic/nsViewportFrame.h
index 3756d4fd8140..a3452e3cf944 100644
--- a/layout/generic/nsViewportFrame.h
+++ b/layout/generic/nsViewportFrame.h
@@ -34,9 +34,9 @@ public:
   {}
   virtual ~ViewportFrame() { } // useful for debugging
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult SetInitialChildList(ChildListID     aListID,
                                        nsFrameList&    aChildList) MOZ_OVERRIDE;
diff --git a/layout/mathml/nsMathMLSelectedFrame.cpp b/layout/mathml/nsMathMLSelectedFrame.cpp
index d385039a76e2..c6dc62b4d719 100644
--- a/layout/mathml/nsMathMLSelectedFrame.cpp
+++ b/layout/mathml/nsMathMLSelectedFrame.cpp
@@ -11,9 +11,9 @@ nsMathMLSelectedFrame::~nsMathMLSelectedFrame()
 }
 
 void
-nsMathMLSelectedFrame::Init(nsIContent*      aContent,
-                            nsIFrame*        aParent,
-                            nsIFrame*        aPrevInFlow)
+nsMathMLSelectedFrame::Init(nsIContent*       aContent,
+                            nsContainerFrame* aParent,
+                            nsIFrame*         aPrevInFlow)
 {
   // Init our local attributes
   mInvalidMarkup = false;
diff --git a/layout/mathml/nsMathMLSelectedFrame.h b/layout/mathml/nsMathMLSelectedFrame.h
index e3f61f67a47f..dc05867b198f 100644
--- a/layout/mathml/nsMathMLSelectedFrame.h
+++ b/layout/mathml/nsMathMLSelectedFrame.h
@@ -11,9 +11,9 @@
 class nsMathMLSelectedFrame : public nsMathMLContainerFrame {
 public:
   virtual void
-  Init(nsIContent*      aContent,
-       nsIFrame*        aParent,
-       nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  Init(nsIContent*       aContent,
+       nsContainerFrame* aParent,
+       nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   NS_IMETHOD
   TransmitAutomaticData() MOZ_OVERRIDE;
diff --git a/layout/mathml/nsMathMLmactionFrame.cpp b/layout/mathml/nsMathMLmactionFrame.cpp
index d4562761a00b..99bda235fe39 100644
--- a/layout/mathml/nsMathMLmactionFrame.cpp
+++ b/layout/mathml/nsMathMLmactionFrame.cpp
@@ -80,9 +80,9 @@ nsMathMLmactionFrame::~nsMathMLmactionFrame()
 }
 
 void
-nsMathMLmactionFrame::Init(nsIContent*      aContent,
-                           nsIFrame*        aParent,
-                           nsIFrame*        aPrevInFlow)
+nsMathMLmactionFrame::Init(nsIContent*       aContent,
+                           nsContainerFrame* aParent,
+                           nsIFrame*         aPrevInFlow)
 {
   // Init our local attributes
 
diff --git a/layout/mathml/nsMathMLmactionFrame.h b/layout/mathml/nsMathMLmactionFrame.h
index 321dc97f7972..5ab623820891 100644
--- a/layout/mathml/nsMathMLmactionFrame.h
+++ b/layout/mathml/nsMathMLmactionFrame.h
@@ -22,9 +22,9 @@ public:
   friend nsIFrame* NS_NewMathMLmactionFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
 
   virtual void
-  Init(nsIContent*      aContent,
-       nsIFrame*        aParent,
-       nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  Init(nsIContent*       aContent,
+       nsContainerFrame* aParent,
+       nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult
   SetInitialChildList(ChildListID     aListID,
diff --git a/layout/mathml/nsMathMLmrootFrame.cpp b/layout/mathml/nsMathMLmrootFrame.cpp
index 390bfc257612..a3eb1cba884f 100644
--- a/layout/mathml/nsMathMLmrootFrame.cpp
+++ b/layout/mathml/nsMathMLmrootFrame.cpp
@@ -46,9 +46,9 @@ nsMathMLmrootFrame::~nsMathMLmrootFrame()
 }
 
 void
-nsMathMLmrootFrame::Init(nsIContent*      aContent,
-                         nsIFrame*        aParent,
-                         nsIFrame*        aPrevInFlow)
+nsMathMLmrootFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   nsMathMLContainerFrame::Init(aContent, aParent, aPrevInFlow);
   
diff --git a/layout/mathml/nsMathMLmrootFrame.h b/layout/mathml/nsMathMLmrootFrame.h
index 4f9f8e27c377..d30e3d14a0c8 100644
--- a/layout/mathml/nsMathMLmrootFrame.h
+++ b/layout/mathml/nsMathMLmrootFrame.h
@@ -27,9 +27,9 @@ public:
   GetAdditionalStyleContext(int32_t aIndex) const MOZ_OVERRIDE;
 
   virtual void
-  Init(nsIContent*      aContent,
-       nsIFrame*        aParent,
-       nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  Init(nsIContent*       aContent,
+       nsContainerFrame* aParent,
+       nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   NS_IMETHOD
   TransmitAutomaticData() MOZ_OVERRIDE;
diff --git a/layout/mathml/nsMathMLmsqrtFrame.cpp b/layout/mathml/nsMathMLmsqrtFrame.cpp
index a91eb2885503..ace431d30beb 100644
--- a/layout/mathml/nsMathMLmsqrtFrame.cpp
+++ b/layout/mathml/nsMathMLmsqrtFrame.cpp
@@ -37,9 +37,9 @@ nsMathMLmsqrtFrame::~nsMathMLmsqrtFrame()
 }
 
 void
-nsMathMLmsqrtFrame::Init(nsIContent*      aContent,
-                         nsIFrame*        aParent,
-                         nsIFrame*        aPrevInFlow)
+nsMathMLmsqrtFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   nsMathMLContainerFrame::Init(aContent, aParent, aPrevInFlow);
   AllocateMathMLChar(NOTATION_RADICAL);
diff --git a/layout/mathml/nsMathMLmsqrtFrame.h b/layout/mathml/nsMathMLmsqrtFrame.h
index cbf638fd82bb..526d77a5d21b 100644
--- a/layout/mathml/nsMathMLmsqrtFrame.h
+++ b/layout/mathml/nsMathMLmsqrtFrame.h
@@ -40,9 +40,9 @@ public:
                                           nsStyleContext* aContext);
 
   virtual void
-  Init(nsIContent* aContent,
-       nsIFrame*   aParent,
-       nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  Init(nsIContent*       aContent,
+       nsContainerFrame* aParent,
+       nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   NS_IMETHOD
   InheritAutomaticData(nsIFrame* aParent) MOZ_OVERRIDE;
diff --git a/layout/svg/SVGFEContainerFrame.cpp b/layout/svg/SVGFEContainerFrame.cpp
index 0c31647ced5b..e7f4e783f0cb 100644
--- a/layout/svg/SVGFEContainerFrame.cpp
+++ b/layout/svg/SVGFEContainerFrame.cpp
@@ -45,9 +45,9 @@ public:
 #endif
 
 #ifdef DEBUG
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
   /**
    * Get the "type" of the frame
@@ -76,9 +76,9 @@ NS_IMPL_FRAMEARENA_HELPERS(SVGFEContainerFrame)
 
 #ifdef DEBUG
 void
-SVGFEContainerFrame::Init(nsIContent* aContent,
-                          nsIFrame* aParent,
-                          nsIFrame* aPrevInFlow)
+SVGFEContainerFrame::Init(nsIContent*       aContent,
+                          nsContainerFrame* aParent,
+                          nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eFILTER),
                "Trying to construct an SVGFEContainerFrame for a "
diff --git a/layout/svg/SVGFEImageFrame.cpp b/layout/svg/SVGFEImageFrame.cpp
index efa5d9f92ab3..5d69a7f9038f 100644
--- a/layout/svg/SVGFEImageFrame.cpp
+++ b/layout/svg/SVGFEImageFrame.cpp
@@ -31,9 +31,9 @@ protected:
 public:
   NS_DECL_FRAMEARENA_HELPERS
 
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
@@ -88,9 +88,9 @@ SVGFEImageFrame::DestroyFrom(nsIFrame* aDestructRoot)
 }
 
 void
-SVGFEImageFrame::Init(nsIContent* aContent,
-                        nsIFrame* aParent,
-                        nsIFrame* aPrevInFlow)
+SVGFEImageFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::feImage),
                "Trying to construct an SVGFEImageFrame for a "
diff --git a/layout/svg/SVGFELeafFrame.cpp b/layout/svg/SVGFELeafFrame.cpp
index a7b04fc30822..de6c4d6631f7 100644
--- a/layout/svg/SVGFELeafFrame.cpp
+++ b/layout/svg/SVGFELeafFrame.cpp
@@ -30,9 +30,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
@@ -74,9 +74,9 @@ NS_IMPL_FRAMEARENA_HELPERS(SVGFELeafFrame)
 
 #ifdef DEBUG
 void
-SVGFELeafFrame::Init(nsIContent* aContent,
-                     nsIFrame* aParent,
-                     nsIFrame* aPrevInFlow)
+SVGFELeafFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eFILTER),
                "Trying to construct an SVGFELeafFrame for a "
diff --git a/layout/svg/SVGTextFrame.cpp b/layout/svg/SVGTextFrame.cpp
index 721e699f71be..3dc3b21c68f7 100644
--- a/layout/svg/SVGTextFrame.cpp
+++ b/layout/svg/SVGTextFrame.cpp
@@ -3154,9 +3154,9 @@ NS_IMPL_FRAMEARENA_HELPERS(SVGTextFrame)
 // nsIFrame methods
 
 void
-SVGTextFrame::Init(nsIContent* aContent,
-                   nsIFrame* aParent,
-                   nsIFrame* aPrevInFlow)
+SVGTextFrame::Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::text), "Content is not an SVG text");
 
diff --git a/layout/svg/SVGTextFrame.h b/layout/svg/SVGTextFrame.h
index ff4ecf04cab1..d0259ca508c0 100644
--- a/layout/svg/SVGTextFrame.h
+++ b/layout/svg/SVGTextFrame.h
@@ -271,9 +271,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
   // nsIFrame:
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult AttributeChanged(int32_t aNamespaceID,
                                     nsIAtom* aAttribute,
diff --git a/layout/svg/SVGViewFrame.cpp b/layout/svg/SVGViewFrame.cpp
index d841a4b60414..cb22910a9618 100644
--- a/layout/svg/SVGViewFrame.cpp
+++ b/layout/svg/SVGViewFrame.cpp
@@ -35,9 +35,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
@@ -79,9 +79,9 @@ NS_IMPL_FRAMEARENA_HELPERS(SVGViewFrame)
 
 #ifdef DEBUG
 void
-SVGViewFrame::Init(nsIContent* aContent,
-                   nsIFrame* aParent,
-                   nsIFrame* aPrevInFlow)
+SVGViewFrame::Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::view),
                "Content is not an SVG view");
diff --git a/layout/svg/nsSVGAFrame.cpp b/layout/svg/nsSVGAFrame.cpp
index b75e9a1e7aa7..9aa4b2ef454e 100644
--- a/layout/svg/nsSVGAFrame.cpp
+++ b/layout/svg/nsSVGAFrame.cpp
@@ -27,9 +27,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   // nsIFrame:
@@ -76,9 +76,9 @@ NS_IMPL_FRAMEARENA_HELPERS(nsSVGAFrame)
 // nsIFrame methods
 #ifdef DEBUG
 void
-nsSVGAFrame::Init(nsIContent* aContent,
-                  nsIFrame* aParent,
-                  nsIFrame* aPrevInFlow)
+nsSVGAFrame::Init(nsIContent*       aContent,
+                  nsContainerFrame* aParent,
+                  nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::a),
                "Trying to construct an SVGAFrame for a "
diff --git a/layout/svg/nsSVGClipPathFrame.cpp b/layout/svg/nsSVGClipPathFrame.cpp
index 4265568e5f45..52499545607f 100644
--- a/layout/svg/nsSVGClipPathFrame.cpp
+++ b/layout/svg/nsSVGClipPathFrame.cpp
@@ -295,9 +295,9 @@ nsSVGClipPathFrame::AttributeChanged(int32_t         aNameSpaceID,
 }
 
 void
-nsSVGClipPathFrame::Init(nsIContent* aContent,
-                         nsIFrame* aParent,
-                         nsIFrame* aPrevInFlow)
+nsSVGClipPathFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::clipPath),
                "Content is not an SVG clipPath!");
diff --git a/layout/svg/nsSVGClipPathFrame.h b/layout/svg/nsSVGClipPathFrame.h
index 01102d1ce2ae..74cbbb004379 100644
--- a/layout/svg/nsSVGClipPathFrame.h
+++ b/layout/svg/nsSVGClipPathFrame.h
@@ -57,9 +57,9 @@ public:
                                     nsIAtom*        aAttribute,
                                     int32_t         aModType) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   /**
    * Get the "type" of the frame
diff --git a/layout/svg/nsSVGContainerFrame.cpp b/layout/svg/nsSVGContainerFrame.cpp
index 58767a2579e0..6c45e9a06dbd 100644
--- a/layout/svg/nsSVGContainerFrame.cpp
+++ b/layout/svg/nsSVGContainerFrame.cpp
@@ -131,9 +131,9 @@ nsSVGContainerFrame::ReflowSVGNonDisplayText(nsIFrame* aContainer)
 }
 
 void
-nsSVGDisplayContainerFrame::Init(nsIContent* aContent,
-                                 nsIFrame* aParent,
-                                 nsIFrame* aPrevInFlow)
+nsSVGDisplayContainerFrame::Init(nsIContent*       aContent,
+                                 nsContainerFrame* aParent,
+                                 nsIFrame*         aPrevInFlow)
 {
   if (!(GetStateBits() & NS_STATE_IS_OUTER_SVG)) {
     AddStateBits(aParent->GetStateBits() & NS_STATE_SVG_CLIPPATH_CHILD);
diff --git a/layout/svg/nsSVGContainerFrame.h b/layout/svg/nsSVGContainerFrame.h
index 76870701c68a..ccf95434aad1 100644
--- a/layout/svg/nsSVGContainerFrame.h
+++ b/layout/svg/nsSVGContainerFrame.h
@@ -133,9 +133,9 @@ public:
                                 nsFrameList&    aFrameList) MOZ_OVERRIDE;
   virtual nsresult RemoveFrame(ChildListID     aListID,
                                nsIFrame*       aOldFrame) MOZ_OVERRIDE;
- virtual void Init(nsIContent*      aContent,
-                   nsIFrame*        aParent,
-                   nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+ virtual void Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
diff --git a/layout/svg/nsSVGFilterFrame.cpp b/layout/svg/nsSVGFilterFrame.cpp
index e00d29916027..13aa7de85229 100644
--- a/layout/svg/nsSVGFilterFrame.cpp
+++ b/layout/svg/nsSVGFilterFrame.cpp
@@ -187,9 +187,9 @@ nsSVGFilterFrame::AttributeChanged(int32_t  aNameSpaceID,
 
 #ifdef DEBUG
 void
-nsSVGFilterFrame::Init(nsIContent* aContent,
-                       nsIFrame* aParent,
-                       nsIFrame* aPrevInFlow)
+nsSVGFilterFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::filter),
                "Content is not an SVG filter");
diff --git a/layout/svg/nsSVGFilterFrame.h b/layout/svg/nsSVGFilterFrame.h
index e2f9b8032379..f1c252d73c5d 100644
--- a/layout/svg/nsSVGFilterFrame.h
+++ b/layout/svg/nsSVGFilterFrame.h
@@ -58,9 +58,9 @@ public:
                                     int32_t         aModType) MOZ_OVERRIDE;
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   /**
diff --git a/layout/svg/nsSVGForeignObjectFrame.cpp b/layout/svg/nsSVGForeignObjectFrame.cpp
index 80a8e9c32284..9643d892ecc5 100644
--- a/layout/svg/nsSVGForeignObjectFrame.cpp
+++ b/layout/svg/nsSVGForeignObjectFrame.cpp
@@ -52,9 +52,9 @@ NS_QUERYFRAME_HEAD(nsSVGForeignObjectFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsSVGForeignObjectFrameBase)
 
 void
-nsSVGForeignObjectFrame::Init(nsIContent* aContent,
-                              nsIFrame*   aParent,
-                              nsIFrame*   aPrevInFlow)
+nsSVGForeignObjectFrame::Init(nsIContent*       aContent,
+                              nsContainerFrame* aParent,
+                              nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::foreignObject),
                "Content is not an SVG foreignObject!");
diff --git a/layout/svg/nsSVGForeignObjectFrame.h b/layout/svg/nsSVGForeignObjectFrame.h
index a52027991a6e..ec584213de3f 100644
--- a/layout/svg/nsSVGForeignObjectFrame.h
+++ b/layout/svg/nsSVGForeignObjectFrame.h
@@ -31,9 +31,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
   // nsIFrame:
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame*   aParent,
-                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
   virtual nsresult  AttributeChanged(int32_t         aNameSpaceID,
                                      nsIAtom*        aAttribute,
diff --git a/layout/svg/nsSVGGFrame.cpp b/layout/svg/nsSVGGFrame.cpp
index f27ee81c5794..bc0d43bf9ae1 100644
--- a/layout/svg/nsSVGGFrame.cpp
+++ b/layout/svg/nsSVGGFrame.cpp
@@ -29,9 +29,9 @@ NS_IMPL_FRAMEARENA_HELPERS(nsSVGGFrame)
 
 #ifdef DEBUG
 void
-nsSVGGFrame::Init(nsIContent* aContent,
-                  nsIFrame* aParent,
-                  nsIFrame* aPrevInFlow)
+nsSVGGFrame::Init(nsIContent*       aContent,
+                  nsContainerFrame* aParent,
+                  nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG() &&
                static_cast<nsSVGElement*>(aContent)->IsTransformable(),
diff --git a/layout/svg/nsSVGGFrame.h b/layout/svg/nsSVGGFrame.h
index 04be3170e32b..467a0f60386c 100644
--- a/layout/svg/nsSVGGFrame.h
+++ b/layout/svg/nsSVGGFrame.h
@@ -24,9 +24,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   /**
diff --git a/layout/svg/nsSVGGradientFrame.cpp b/layout/svg/nsSVGGradientFrame.cpp
index 8888853e59ea..e269c30b1adf 100644
--- a/layout/svg/nsSVGGradientFrame.cpp
+++ b/layout/svg/nsSVGGradientFrame.cpp
@@ -400,9 +400,9 @@ nsSVGGradientFrame::GetStopFrames(nsTArray<nsIFrame*>* aStopFrames)
 
 #ifdef DEBUG
 void
-nsSVGLinearGradientFrame::Init(nsIContent* aContent,
-                               nsIFrame* aParent,
-                               nsIFrame* aPrevInFlow)
+nsSVGLinearGradientFrame::Init(nsIContent*       aContent,
+                               nsContainerFrame* aParent,
+                               nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::linearGradient),
                "Content is not an SVG linearGradient");
@@ -509,9 +509,9 @@ nsSVGLinearGradientFrame::CreateGradient()
 
 #ifdef DEBUG
 void
-nsSVGRadialGradientFrame::Init(nsIContent* aContent,
-                               nsIFrame* aParent,
-                               nsIFrame* aPrevInFlow)
+nsSVGRadialGradientFrame::Init(nsIContent*       aContent,
+                               nsContainerFrame* aParent,
+                               nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::radialGradient),
                "Content is not an SVG radialGradient");
diff --git a/layout/svg/nsSVGGradientFrame.h b/layout/svg/nsSVGGradientFrame.h
index f05b00bbba8a..b01a9fdda462 100644
--- a/layout/svg/nsSVGGradientFrame.h
+++ b/layout/svg/nsSVGGradientFrame.h
@@ -138,9 +138,9 @@ public:
 
   // nsIFrame interface:
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   virtual nsIAtom* GetType() const MOZ_OVERRIDE;  // frame type: nsGkAtoms::svgLinearGradientFrame
@@ -183,9 +183,9 @@ public:
 
   // nsIFrame interface:
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   virtual nsIAtom* GetType() const MOZ_OVERRIDE;  // frame type: nsGkAtoms::svgRadialGradientFrame
diff --git a/layout/svg/nsSVGImageFrame.cpp b/layout/svg/nsSVGImageFrame.cpp
index aa47e6c98ae3..a79af14dc0a9 100644
--- a/layout/svg/nsSVGImageFrame.cpp
+++ b/layout/svg/nsSVGImageFrame.cpp
@@ -73,9 +73,9 @@ public:
   virtual nsresult  AttributeChanged(int32_t         aNameSpaceID,
                                      nsIAtom*        aAttribute,
                                      int32_t         aModType) MOZ_OVERRIDE;
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
   /**
@@ -140,9 +140,9 @@ nsSVGImageFrame::~nsSVGImageFrame()
 }
 
 void
-nsSVGImageFrame::Init(nsIContent* aContent,
-                      nsIFrame* aParent,
-                      nsIFrame* aPrevInFlow)
+nsSVGImageFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::image),
                "Content is not an SVG image!");
diff --git a/layout/svg/nsSVGInnerSVGFrame.cpp b/layout/svg/nsSVGInnerSVGFrame.cpp
index 0ac21d3116f2..a72090f8ba01 100644
--- a/layout/svg/nsSVGInnerSVGFrame.cpp
+++ b/layout/svg/nsSVGInnerSVGFrame.cpp
@@ -37,9 +37,9 @@ NS_QUERYFRAME_TAIL_INHERITING(nsSVGInnerSVGFrameBase)
 
 #ifdef DEBUG
 void
-nsSVGInnerSVGFrame::Init(nsIContent* aContent,
-                         nsIFrame* aParent,
-                         nsIFrame* aPrevInFlow)
+nsSVGInnerSVGFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::svg),
                "Content is not an SVG 'svg' element!");
diff --git a/layout/svg/nsSVGInnerSVGFrame.h b/layout/svg/nsSVGInnerSVGFrame.h
index daee9bb37b9c..6056f63fa301 100644
--- a/layout/svg/nsSVGInnerSVGFrame.h
+++ b/layout/svg/nsSVGInnerSVGFrame.h
@@ -29,9 +29,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   /**
diff --git a/layout/svg/nsSVGMarkerFrame.cpp b/layout/svg/nsSVGMarkerFrame.cpp
index 68c9501a7493..c880200bc641 100644
--- a/layout/svg/nsSVGMarkerFrame.cpp
+++ b/layout/svg/nsSVGMarkerFrame.cpp
@@ -51,9 +51,9 @@ nsSVGMarkerFrame::AttributeChanged(int32_t  aNameSpaceID,
 
 #ifdef DEBUG
 void
-nsSVGMarkerFrame::Init(nsIContent* aContent,
-                       nsIFrame* aParent,
-                       nsIFrame* aPrevInFlow)
+nsSVGMarkerFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::marker), "Content is not an SVG marker");
 
@@ -255,9 +255,9 @@ NS_IMPL_FRAMEARENA_HELPERS(nsSVGMarkerAnonChildFrame)
 
 #ifdef DEBUG
 void
-nsSVGMarkerAnonChildFrame::Init(nsIContent* aContent,
-                                nsIFrame* aParent,
-                                nsIFrame* aPrevInFlow)
+nsSVGMarkerAnonChildFrame::Init(nsIContent*       aContent,
+                                nsContainerFrame* aParent,
+                                nsIFrame*         aPrevInFlow)
 {
   NS_ABORT_IF_FALSE(aParent->GetType() == nsGkAtoms::svgMarkerFrame,
                     "Unexpected parent");
diff --git a/layout/svg/nsSVGMarkerFrame.h b/layout/svg/nsSVGMarkerFrame.h
index c6c3c33589cb..3b636a5f1ca9 100644
--- a/layout/svg/nsSVGMarkerFrame.h
+++ b/layout/svg/nsSVGMarkerFrame.h
@@ -48,9 +48,9 @@ public:
 
   // nsIFrame interface:
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
@@ -154,9 +154,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame* aParent,
-                    nsIFrame* aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
 #ifdef DEBUG_FRAME_DUMP
diff --git a/layout/svg/nsSVGMaskFrame.cpp b/layout/svg/nsSVGMaskFrame.cpp
index 4ce0cc093f68..cff18465f15f 100644
--- a/layout/svg/nsSVGMaskFrame.cpp
+++ b/layout/svg/nsSVGMaskFrame.cpp
@@ -288,9 +288,9 @@ nsSVGMaskFrame::AttributeChanged(int32_t  aNameSpaceID,
 
 #ifdef DEBUG
 void
-nsSVGMaskFrame::Init(nsIContent* aContent,
-                     nsIFrame* aParent,
-                     nsIFrame* aPrevInFlow)
+nsSVGMaskFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::mask),
                "Content is not an SVG mask");
diff --git a/layout/svg/nsSVGMaskFrame.h b/layout/svg/nsSVGMaskFrame.h
index f3be8efa8c65..72c407c0e30b 100644
--- a/layout/svg/nsSVGMaskFrame.h
+++ b/layout/svg/nsSVGMaskFrame.h
@@ -43,9 +43,9 @@ public:
                                     int32_t         aModType) MOZ_OVERRIDE;
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
diff --git a/layout/svg/nsSVGOuterSVGFrame.cpp b/layout/svg/nsSVGOuterSVGFrame.cpp
index 6c4254021e4d..3b346e8d0125 100644
--- a/layout/svg/nsSVGOuterSVGFrame.cpp
+++ b/layout/svg/nsSVGOuterSVGFrame.cpp
@@ -74,9 +74,9 @@ nsSVGOuterSVGFrame::nsSVGOuterSVGFrame(nsStyleContext* aContext)
 }
 
 void
-nsSVGOuterSVGFrame::Init(nsIContent* aContent,
-                         nsIFrame* aParent,
-                         nsIFrame* aPrevInFlow)
+nsSVGOuterSVGFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent,
+                         nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::svg),
                "Content is not an SVG 'svg' element!");
@@ -912,9 +912,9 @@ NS_IMPL_FRAMEARENA_HELPERS(nsSVGOuterSVGAnonChildFrame)
 
 #ifdef DEBUG
 void
-nsSVGOuterSVGAnonChildFrame::Init(nsIContent* aContent,
-                                  nsIFrame* aParent,
-                                  nsIFrame* aPrevInFlow)
+nsSVGOuterSVGAnonChildFrame::Init(nsIContent*       aContent,
+                                  nsContainerFrame* aParent,
+                                  nsIFrame*         aPrevInFlow)
 {
   NS_ABORT_IF_FALSE(aParent->GetType() == nsGkAtoms::svgOuterSVGFrame,
                     "Unexpected parent");
diff --git a/layout/svg/nsSVGOuterSVGFrame.h b/layout/svg/nsSVGOuterSVGFrame.h
index e5d91f771896..2c1d8aa56b42 100644
--- a/layout/svg/nsSVGOuterSVGFrame.h
+++ b/layout/svg/nsSVGOuterSVGFrame.h
@@ -64,9 +64,9 @@ public:
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsSplittableType GetSplittableType() const MOZ_OVERRIDE;
 
@@ -245,9 +245,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame* aParent,
-                    nsIFrame* aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
 #ifdef DEBUG_FRAME_DUMP
diff --git a/layout/svg/nsSVGPathGeometryFrame.cpp b/layout/svg/nsSVGPathGeometryFrame.cpp
index a56089bc75d6..f8ab0f296acf 100644
--- a/layout/svg/nsSVGPathGeometryFrame.cpp
+++ b/layout/svg/nsSVGPathGeometryFrame.cpp
@@ -104,9 +104,9 @@ nsDisplaySVGPathGeometry::Paint(nsDisplayListBuilder* aBuilder,
 // nsIFrame methods
 
 void
-nsSVGPathGeometryFrame::Init(nsIContent* aContent,
-                             nsIFrame* aParent,
-                             nsIFrame* aPrevInFlow)
+nsSVGPathGeometryFrame::Init(nsIContent*       aContent,
+                             nsContainerFrame* aParent,
+                             nsIFrame*         aPrevInFlow)
 {
   AddStateBits(aParent->GetStateBits() & NS_STATE_SVG_CLIPPATH_CHILD);
   nsSVGPathGeometryFrameBase::Init(aContent, aParent, aPrevInFlow);
diff --git a/layout/svg/nsSVGPathGeometryFrame.h b/layout/svg/nsSVGPathGeometryFrame.h
index 38ae06f0000d..14f64e472c8f 100644
--- a/layout/svg/nsSVGPathGeometryFrame.h
+++ b/layout/svg/nsSVGPathGeometryFrame.h
@@ -52,9 +52,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
   // nsIFrame interface:
-  virtual void Init(nsIContent* aContent,
-                    nsIFrame* aParent,
-                    nsIFrame* aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
   {
diff --git a/layout/svg/nsSVGPatternFrame.cpp b/layout/svg/nsSVGPatternFrame.cpp
index fa35d73fb289..f77d7278485e 100644
--- a/layout/svg/nsSVGPatternFrame.cpp
+++ b/layout/svg/nsSVGPatternFrame.cpp
@@ -102,9 +102,9 @@ nsSVGPatternFrame::AttributeChanged(int32_t         aNameSpaceID,
 
 #ifdef DEBUG
 void
-nsSVGPatternFrame::Init(nsIContent* aContent,
-                        nsIFrame* aParent,
-                        nsIFrame* aPrevInFlow)
+nsSVGPatternFrame::Init(nsIContent*       aContent,
+                        nsContainerFrame* aParent,
+                        nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::pattern), "Content is not an SVG pattern");
 
diff --git a/layout/svg/nsSVGPatternFrame.h b/layout/svg/nsSVGPatternFrame.h
index f069944bef27..247a7c42750e 100644
--- a/layout/svg/nsSVGPatternFrame.h
+++ b/layout/svg/nsSVGPatternFrame.h
@@ -61,9 +61,9 @@ public:
                                     int32_t         aModType) MOZ_OVERRIDE;
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   /**
diff --git a/layout/svg/nsSVGStopFrame.cpp b/layout/svg/nsSVGStopFrame.cpp
index c20c8c236c4c..2e2bad662264 100644
--- a/layout/svg/nsSVGStopFrame.cpp
+++ b/layout/svg/nsSVGStopFrame.cpp
@@ -31,9 +31,9 @@ public:
 
   // nsIFrame interface:
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
@@ -74,9 +74,9 @@ NS_IMPL_FRAMEARENA_HELPERS(nsSVGStopFrame)
 
 #ifdef DEBUG
 void
-nsSVGStopFrame::Init(nsIContent* aContent,
-                     nsIFrame* aParent,
-                     nsIFrame* aPrevInFlow)
+nsSVGStopFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::stop), "Content is not a stop element");
 
diff --git a/layout/svg/nsSVGSwitchFrame.cpp b/layout/svg/nsSVGSwitchFrame.cpp
index 7c3bc678891d..88ebd3e5fcaa 100644
--- a/layout/svg/nsSVGSwitchFrame.cpp
+++ b/layout/svg/nsSVGSwitchFrame.cpp
@@ -28,9 +28,9 @@ public:
   NS_DECL_FRAMEARENA_HELPERS
 
 #ifdef DEBUG
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 #endif
 
   /**
@@ -78,9 +78,9 @@ NS_IMPL_FRAMEARENA_HELPERS(nsSVGSwitchFrame)
 
 #ifdef DEBUG
 void
-nsSVGSwitchFrame::Init(nsIContent* aContent,
-                       nsIFrame* aParent,
-                       nsIFrame* aPrevInFlow)
+nsSVGSwitchFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::svgSwitch),
                "Content is not an SVG switch");
diff --git a/layout/svg/nsSVGUseFrame.cpp b/layout/svg/nsSVGUseFrame.cpp
index 7c628513edaf..148f555b18bd 100644
--- a/layout/svg/nsSVGUseFrame.cpp
+++ b/layout/svg/nsSVGUseFrame.cpp
@@ -32,9 +32,9 @@ public:
 
   
   // nsIFrame interface:
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult  AttributeChanged(int32_t         aNameSpaceID,
                                      nsIAtom*        aAttribute,
@@ -99,9 +99,9 @@ NS_QUERYFRAME_TAIL_INHERITING(nsSVGUseFrameBase)
 // nsIFrame methods:
 
 void
-nsSVGUseFrame::Init(nsIContent* aContent,
-                    nsIFrame* aParent,
-                    nsIFrame* aPrevInFlow)
+nsSVGUseFrame::Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow)
 {
   NS_ASSERTION(aContent->IsSVG(nsGkAtoms::use),
                "Content is not an SVG use!");
diff --git a/layout/tables/nsTableCellFrame.cpp b/layout/tables/nsTableCellFrame.cpp
index 61cc7a4c02a7..07103519a976 100644
--- a/layout/tables/nsTableCellFrame.cpp
+++ b/layout/tables/nsTableCellFrame.cpp
@@ -67,9 +67,9 @@ nsTableCellFrame::GetNextCell() const
 }
 
 void
-nsTableCellFrame::Init(nsIContent*      aContent,
-                       nsIFrame*        aParent,
-                       nsIFrame*        aPrevInFlow)
+nsTableCellFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   // Let the base class do its initialization
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
diff --git a/layout/tables/nsTableCellFrame.h b/layout/tables/nsTableCellFrame.h
index 1600b38249e6..367ff871af14 100644
--- a/layout/tables/nsTableCellFrame.h
+++ b/layout/tables/nsTableCellFrame.h
@@ -43,9 +43,9 @@ public:
   nsTableCellFrame(nsStyleContext* aContext);
   ~nsTableCellFrame();
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/tables/nsTableFrame.cpp b/layout/tables/nsTableFrame.cpp
index 236a568b07af..e8d4ddb55c92 100644
--- a/layout/tables/nsTableFrame.cpp
+++ b/layout/tables/nsTableFrame.cpp
@@ -164,9 +164,9 @@ nsTableFrame::nsTableFrame(nsStyleContext* aContext)
 }
 
 void
-nsTableFrame::Init(nsIContent*      aContent,
-                   nsIFrame*        aParent,
-                   nsIFrame*        aPrevInFlow)
+nsTableFrame::Init(nsIContent*       aContent,
+                   nsContainerFrame* aParent,
+                   nsIFrame*         aPrevInFlow)
 {
   NS_PRECONDITION(!mCellMap, "Init called twice");
   NS_PRECONDITION(!aPrevInFlow ||
diff --git a/layout/tables/nsTableFrame.h b/layout/tables/nsTableFrame.h
index d69755425f10..cae8a740f88e 100644
--- a/layout/tables/nsTableFrame.h
+++ b/layout/tables/nsTableFrame.h
@@ -128,9 +128,9 @@ public:
   /** sets defaults for table-specific style.
     * @see nsIFrame::Init 
     */
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   static float GetTwipsToPixels(nsPresContext* aPresContext);
 
diff --git a/layout/tables/nsTableRowFrame.cpp b/layout/tables/nsTableRowFrame.cpp
index 8b644b97da7b..349ff19e2750 100644
--- a/layout/tables/nsTableRowFrame.cpp
+++ b/layout/tables/nsTableRowFrame.cpp
@@ -132,9 +132,9 @@ nsTableRowFrame::~nsTableRowFrame()
 }
 
 void
-nsTableRowFrame::Init(nsIContent*      aContent,
-                      nsIFrame*        aParent,
-                      nsIFrame*        aPrevInFlow)
+nsTableRowFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   // Let the base class do its initialization
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
diff --git a/layout/tables/nsTableRowFrame.h b/layout/tables/nsTableRowFrame.h
index 765a5352e5c2..3370cd17cb44 100644
--- a/layout/tables/nsTableRowFrame.h
+++ b/layout/tables/nsTableRowFrame.h
@@ -33,9 +33,9 @@ public:
 
   virtual ~nsTableRowFrame();
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/xul/nsBoxFrame.cpp b/layout/xul/nsBoxFrame.cpp
index 2949098b5a29..a4ef1d2fe74a 100644
--- a/layout/xul/nsBoxFrame.cpp
+++ b/layout/xul/nsBoxFrame.cpp
@@ -170,9 +170,9 @@ nsBoxFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
  * Initialize us. This is a good time to get the alignment of the box
  */
 void
-nsBoxFrame::Init(nsIContent*      aContent,
-                 nsIFrame*        aParent,
-                 nsIFrame*        aPrevInFlow)
+nsBoxFrame::Init(nsIContent*       aContent,
+                 nsContainerFrame* aParent,
+                 nsIFrame*         aPrevInFlow)
 {
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsBoxFrame.h b/layout/xul/nsBoxFrame.h
index 548c4854c402..5cf77ef96fb5 100644
--- a/layout/xul/nsBoxFrame.h
+++ b/layout/xul/nsBoxFrame.h
@@ -71,9 +71,9 @@ public:
 
   // ----- public methods -------
   
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
  
   virtual nsresult AttributeChanged(int32_t         aNameSpaceID,
diff --git a/layout/xul/nsDeckFrame.cpp b/layout/xul/nsDeckFrame.cpp
index c8f6767072da..a678d0a5b27e 100644
--- a/layout/xul/nsDeckFrame.cpp
+++ b/layout/xul/nsDeckFrame.cpp
@@ -75,9 +75,9 @@ nsDeckFrame::AttributeChanged(int32_t         aNameSpaceID,
 }
 
 void
-nsDeckFrame::Init(nsIContent*     aContent,
-                  nsIFrame*       aParent,
-                  nsIFrame*       aPrevInFlow)
+nsDeckFrame::Init(nsIContent*       aContent,
+                  nsContainerFrame* aParent,
+                  nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsDeckFrame.h b/layout/xul/nsDeckFrame.h
index 5850d9f4e27e..2ac9cfbee964 100644
--- a/layout/xul/nsDeckFrame.h
+++ b/layout/xul/nsDeckFrame.h
@@ -41,9 +41,9 @@ public:
                                            const nsRect&           aDirtyRect,
                                            const nsDisplayListSet& aLists) MOZ_OVERRIDE;
                                          
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsIAtom* GetType() const MOZ_OVERRIDE;
 
diff --git a/layout/xul/nsImageBoxFrame.cpp b/layout/xul/nsImageBoxFrame.cpp
index 8321c55b884e..96830aca95b7 100644
--- a/layout/xul/nsImageBoxFrame.cpp
+++ b/layout/xul/nsImageBoxFrame.cpp
@@ -183,9 +183,9 @@ nsImageBoxFrame::DestroyFrom(nsIFrame* aDestructRoot)
 
 
 void
-nsImageBoxFrame::Init(nsIContent*      aContent,
-                      nsIFrame*        aParent,
-                      nsIFrame*        aPrevInFlow)
+nsImageBoxFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   if (!mListener) {
     nsImageBoxListener *listener = new nsImageBoxListener();
diff --git a/layout/xul/nsImageBoxFrame.h b/layout/xul/nsImageBoxFrame.h
index 78b8701590ef..261adff35ea5 100644
--- a/layout/xul/nsImageBoxFrame.h
+++ b/layout/xul/nsImageBoxFrame.h
@@ -53,9 +53,9 @@ public:
 
   friend nsIFrame* NS_NewImageBoxFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         asPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult AttributeChanged(int32_t aNameSpaceID,
                                     nsIAtom* aAttribute,
diff --git a/layout/xul/nsLeafBoxFrame.cpp b/layout/xul/nsLeafBoxFrame.cpp
index 8e3e7f515091..07fd078bdeb0 100644
--- a/layout/xul/nsLeafBoxFrame.cpp
+++ b/layout/xul/nsLeafBoxFrame.cpp
@@ -56,10 +56,9 @@ nsLeafBoxFrame::GetBoxName(nsAutoString& aName)
  * Initialize us. This is a good time to get the alignment of the box
  */
 void
-nsLeafBoxFrame::Init(
-              nsIContent*      aContent,
-              nsIFrame*        aParent,
-              nsIFrame*        aPrevInFlow)
+nsLeafBoxFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
   nsLeafFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsLeafBoxFrame.h b/layout/xul/nsLeafBoxFrame.h
index 7f1d0b5983ab..b73dcea1e48d 100644
--- a/layout/xul/nsLeafBoxFrame.h
+++ b/layout/xul/nsLeafBoxFrame.h
@@ -56,9 +56,9 @@ public:
 
   virtual nsresult CharacterDataChanged(CharacterDataChangeInfo* aInfo) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         asPrevInFlow) MOZ_OVERRIDE;
 
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
diff --git a/layout/xul/nsListBoxBodyFrame.cpp b/layout/xul/nsListBoxBodyFrame.cpp
index 14234f61e951..8f7f2d206650 100644
--- a/layout/xul/nsListBoxBodyFrame.cpp
+++ b/layout/xul/nsListBoxBodyFrame.cpp
@@ -179,9 +179,9 @@ NS_QUERYFRAME_TAIL_INHERITING(nsBoxFrame)
 ////////// nsIFrame /////////////////
 
 void
-nsListBoxBodyFrame::Init(nsIContent*     aContent,
-                         nsIFrame*       aParent, 
-                         nsIFrame*       aPrevInFlow)
+nsListBoxBodyFrame::Init(nsIContent*       aContent,
+                         nsContainerFrame* aParent, 
+                         nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
   nsIScrollableFrame* scrollFrame = nsLayoutUtils::GetScrollableFrameFor(this);
diff --git a/layout/xul/nsListBoxBodyFrame.h b/layout/xul/nsListBoxBodyFrame.h
index eaff459b703c..16195204f14a 100644
--- a/layout/xul/nsListBoxBodyFrame.h
+++ b/layout/xul/nsListBoxBodyFrame.h
@@ -48,9 +48,9 @@ public:
                                           nsStyleContext* aContext);
   
   // nsIFrame
-  virtual void Init(nsIContent*     aContent,
-                    nsIFrame*       aParent, 
-                    nsIFrame*       aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent, 
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
   virtual nsresult AttributeChanged(int32_t aNameSpaceID, nsIAtom* aAttribute, int32_t aModType) MOZ_OVERRIDE;
diff --git a/layout/xul/nsMenuBarFrame.cpp b/layout/xul/nsMenuBarFrame.cpp
index d797b736760a..9c7b913adec3 100644
--- a/layout/xul/nsMenuBarFrame.cpp
+++ b/layout/xul/nsMenuBarFrame.cpp
@@ -60,9 +60,9 @@ nsMenuBarFrame::nsMenuBarFrame(nsIPresShell* aShell, nsStyleContext* aContext):
 } // cntr
 
 void
-nsMenuBarFrame::Init(nsIContent*      aContent,
-                     nsIFrame*        aParent,
-                     nsIFrame*        aPrevInFlow)
+nsMenuBarFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsMenuBarFrame.h b/layout/xul/nsMenuBarFrame.h
index 02ec7c5d8d16..c8452d6b82b5 100644
--- a/layout/xul/nsMenuBarFrame.h
+++ b/layout/xul/nsMenuBarFrame.h
@@ -50,9 +50,9 @@ public:
   void InstallKeyboardNavigator();
   void RemoveKeyboardNavigator();
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/xul/nsMenuFrame.cpp b/layout/xul/nsMenuFrame.cpp
index 19a27d861147..0178a723c6cf 100644
--- a/layout/xul/nsMenuFrame.cpp
+++ b/layout/xul/nsMenuFrame.cpp
@@ -241,9 +241,9 @@ public:
 };
 
 void
-nsMenuFrame::Init(nsIContent*      aContent,
-                  nsIFrame*        aParent,
-                  nsIFrame*        aPrevInFlow)
+nsMenuFrame::Init(nsIContent*       aContent,
+                  nsContainerFrame* aParent,
+                  nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsMenuFrame.h b/layout/xul/nsMenuFrame.h
index 36acb124e404..6502d63ad0b3 100644
--- a/layout/xul/nsMenuFrame.h
+++ b/layout/xul/nsMenuFrame.h
@@ -85,9 +85,9 @@ public:
   virtual nsSize GetMinSize(nsBoxLayoutState& aBoxLayoutState) MOZ_OVERRIDE;
   virtual nsSize GetPrefSize(nsBoxLayoutState& aBoxLayoutState) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
 #ifdef DEBUG_LAYOUT
   virtual nsresult SetDebug(nsBoxLayoutState& aState, bool aDebug) MOZ_OVERRIDE;
diff --git a/layout/xul/nsMenuPopupFrame.cpp b/layout/xul/nsMenuPopupFrame.cpp
index 134e4c3ec5f3..13d2a7d80f6c 100644
--- a/layout/xul/nsMenuPopupFrame.cpp
+++ b/layout/xul/nsMenuPopupFrame.cpp
@@ -111,9 +111,9 @@ nsMenuPopupFrame::nsMenuPopupFrame(nsIPresShell* aShell, nsStyleContext* aContex
 
 
 void
-nsMenuPopupFrame::Init(nsIContent*      aContent,
-                       nsIFrame*        aParent,
-                       nsIFrame*        aPrevInFlow)
+nsMenuPopupFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsMenuPopupFrame.h b/layout/xul/nsMenuPopupFrame.h
index 38822d026d7c..6bac410a0763 100644
--- a/layout/xul/nsMenuPopupFrame.h
+++ b/layout/xul/nsMenuPopupFrame.h
@@ -173,9 +173,9 @@ public:
   void AttachedDismissalListener();
 
   // Overridden methods
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult AttributeChanged(int32_t aNameSpaceID,
                                     nsIAtom* aAttribute,
diff --git a/layout/xul/nsPopupSetFrame.cpp b/layout/xul/nsPopupSetFrame.cpp
index 477beff9d3eb..2a7ce6695fae 100644
--- a/layout/xul/nsPopupSetFrame.cpp
+++ b/layout/xul/nsPopupSetFrame.cpp
@@ -23,9 +23,9 @@ NS_NewPopupSetFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 NS_IMPL_FRAMEARENA_HELPERS(nsPopupSetFrame)
 
 void
-nsPopupSetFrame::Init(nsIContent*      aContent,
-                      nsIFrame*        aParent,
-                      nsIFrame*        aPrevInFlow)
+nsPopupSetFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsPopupSetFrame.h b/layout/xul/nsPopupSetFrame.h
index 7f0dcd87cb10..e33d665b44a5 100644
--- a/layout/xul/nsPopupSetFrame.h
+++ b/layout/xul/nsPopupSetFrame.h
@@ -23,9 +23,9 @@ public:
 
   ~nsPopupSetFrame() {}
   
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual nsresult AppendFrames(ChildListID     aListID,
                                 nsFrameList&    aFrameList) MOZ_OVERRIDE;
   virtual nsresult RemoveFrame(ChildListID     aListID,
diff --git a/layout/xul/nsScrollbarFrame.cpp b/layout/xul/nsScrollbarFrame.cpp
index 6e4625991442..77603290b668 100644
--- a/layout/xul/nsScrollbarFrame.cpp
+++ b/layout/xul/nsScrollbarFrame.cpp
@@ -40,9 +40,9 @@ NS_QUERYFRAME_HEAD(nsScrollbarFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsBoxFrame)
 
 void
-nsScrollbarFrame::Init(nsIContent* aContent,
-                       nsIFrame*   aParent,
-                       nsIFrame*   aPrevInFlow)
+nsScrollbarFrame::Init(nsIContent*       aContent,
+                       nsContainerFrame* aParent,
+                       nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsScrollbarFrame.h b/layout/xul/nsScrollbarFrame.h
index 551d5ea442e9..ef260622c141 100644
--- a/layout/xul/nsScrollbarFrame.h
+++ b/layout/xul/nsScrollbarFrame.h
@@ -56,9 +56,9 @@ public:
                            mozilla::WidgetGUIEvent* aEvent,
                            nsEventStatus* aEventStatus) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void Reflow(nsPresContext*           aPresContext,
                       nsHTMLReflowMetrics&     aDesiredSize,
diff --git a/layout/xul/nsSliderFrame.cpp b/layout/xul/nsSliderFrame.cpp
index b3a259631a3b..5d5775b08d48 100644
--- a/layout/xul/nsSliderFrame.cpp
+++ b/layout/xul/nsSliderFrame.cpp
@@ -74,9 +74,9 @@ nsSliderFrame::~nsSliderFrame()
 }
 
 void
-nsSliderFrame::Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow)
+nsSliderFrame::Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsSliderFrame.h b/layout/xul/nsSliderFrame.h
index e7a63ed755e0..cb53a11de7ad 100644
--- a/layout/xul/nsSliderFrame.h
+++ b/layout/xul/nsSliderFrame.h
@@ -82,9 +82,9 @@ public:
                                     nsIAtom* aAttribute,
                                     int32_t aModType) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         asPrevInFlow) MOZ_OVERRIDE;
 
 
   virtual nsresult HandleEvent(nsPresContext* aPresContext,
diff --git a/layout/xul/nsSplitterFrame.cpp b/layout/xul/nsSplitterFrame.cpp
index d686b698ee92..74329df87a6f 100644
--- a/layout/xul/nsSplitterFrame.cpp
+++ b/layout/xul/nsSplitterFrame.cpp
@@ -262,9 +262,9 @@ nsSplitterFrame::AttributeChanged(int32_t aNameSpaceID,
  * Initialize us. If we are in a box get our alignment so we know what direction we are
  */
 void
-nsSplitterFrame::Init(nsIContent*      aContent,
-                      nsIFrame*        aParent,
-                      nsIFrame*        aPrevInFlow)
+nsSplitterFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   MOZ_ASSERT(!mInner);
   mInner = new nsSplitterFrameInner(this);
diff --git a/layout/xul/nsSplitterFrame.h b/layout/xul/nsSplitterFrame.h
index a65ec1717aca..397781a21d44 100644
--- a/layout/xul/nsSplitterFrame.h
+++ b/layout/xul/nsSplitterFrame.h
@@ -37,9 +37,9 @@ public:
                                     nsIAtom* aAttribute,
                                     int32_t aModType) MOZ_OVERRIDE;
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual nsresult GetCursor(const nsPoint&    aPoint,
                              nsIFrame::Cursor& aCursor) MOZ_OVERRIDE;
diff --git a/layout/xul/nsTextBoxFrame.cpp b/layout/xul/nsTextBoxFrame.cpp
index a7f9996676c3..434a17a53506 100644
--- a/layout/xul/nsTextBoxFrame.cpp
+++ b/layout/xul/nsTextBoxFrame.cpp
@@ -107,9 +107,9 @@ nsTextBoxFrame::~nsTextBoxFrame()
 
 
 void
-nsTextBoxFrame::Init(nsIContent*      aContent,
-                     nsIFrame*        aParent,
-                     nsIFrame*        aPrevInFlow)
+nsTextBoxFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
     nsTextBoxFrameSuper::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsTextBoxFrame.h b/layout/xul/nsTextBoxFrame.h
index 691ffdc6c685..320b030dc6d4 100644
--- a/layout/xul/nsTextBoxFrame.h
+++ b/layout/xul/nsTextBoxFrame.h
@@ -29,9 +29,9 @@ public:
 
   friend nsIFrame* NS_NewTextBoxFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        asPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         asPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/xul/nsXULLabelFrame.cpp b/layout/xul/nsXULLabelFrame.cpp
index 5331329ea030..26619b1810a9 100644
--- a/layout/xul/nsXULLabelFrame.cpp
+++ b/layout/xul/nsXULLabelFrame.cpp
@@ -64,9 +64,9 @@ nsXULLabelFrame::RegUnregAccessKey(bool aDoReg)
 // nsIFrame
 
 void
-nsXULLabelFrame::Init(nsIContent*      aContent,
-                      nsIFrame*        aParent,
-                      nsIFrame*        aPrevInFlow)
+nsXULLabelFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   nsBlockFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/nsXULLabelFrame.h b/layout/xul/nsXULLabelFrame.h
index d5f54e0ba66d..84bf553e4e8a 100644
--- a/layout/xul/nsXULLabelFrame.h
+++ b/layout/xul/nsXULLabelFrame.h
@@ -24,9 +24,9 @@ public:
                                        nsStyleContext *aContext);
   
   // nsIFrame
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
diff --git a/layout/xul/tree/nsTreeBodyFrame.cpp b/layout/xul/tree/nsTreeBodyFrame.cpp
index 7f33ed2ae51a..02c15c0dc177 100644
--- a/layout/xul/tree/nsTreeBodyFrame.cpp
+++ b/layout/xul/tree/nsTreeBodyFrame.cpp
@@ -161,9 +161,9 @@ AdjustForBorderPadding(nsStyleContext* aContext, nsRect& aRect)
 }
 
 void
-nsTreeBodyFrame::Init(nsIContent*     aContent,
-                      nsIFrame*       aParent,
-                      nsIFrame*       aPrevInFlow)
+nsTreeBodyFrame::Init(nsIContent*       aContent,
+                      nsContainerFrame* aParent,
+                      nsIFrame*         aPrevInFlow)
 {
   nsLeafBoxFrame::Init(aContent, aParent, aPrevInFlow);
 
diff --git a/layout/xul/tree/nsTreeBodyFrame.h b/layout/xul/tree/nsTreeBodyFrame.h
index fb1f8b758f70..c0ea326064c5 100644
--- a/layout/xul/tree/nsTreeBodyFrame.h
+++ b/layout/xul/tree/nsTreeBodyFrame.h
@@ -145,9 +145,9 @@ public:
   }
 
   // Overridden from nsIFrame to cache our pres context.
-  virtual void Init(nsIContent*     aContent,
-                    nsIFrame*       aParent,
-                    nsIFrame*       aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
 
   virtual nsresult GetCursor(const nsPoint& aPoint,
diff --git a/layout/xul/tree/nsTreeColFrame.cpp b/layout/xul/tree/nsTreeColFrame.cpp
index 37f1cc6f6099..2fc107e0b1bb 100644
--- a/layout/xul/tree/nsTreeColFrame.cpp
+++ b/layout/xul/tree/nsTreeColFrame.cpp
@@ -37,9 +37,9 @@ nsTreeColFrame::~nsTreeColFrame()
 }
 
 void
-nsTreeColFrame::Init(nsIContent*      aContent,
-                     nsIFrame*        aParent,
-                     nsIFrame*        aPrevInFlow)
+nsTreeColFrame::Init(nsIContent*       aContent,
+                     nsContainerFrame* aParent,
+                     nsIFrame*         aPrevInFlow)
 {
   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
   InvalidateColumns();
diff --git a/layout/xul/tree/nsTreeColFrame.h b/layout/xul/tree/nsTreeColFrame.h
index 7501f657a0ed..f32f2aa17854 100644
--- a/layout/xul/tree/nsTreeColFrame.h
+++ b/layout/xul/tree/nsTreeColFrame.h
@@ -20,9 +20,9 @@ public:
                  nsStyleContext* aContext):
     nsBoxFrame(aPresShell, aContext) {}
 
-  virtual void Init(nsIContent*      aContent,
-                    nsIFrame*        aParent,
-                    nsIFrame*        aPrevInFlow) MOZ_OVERRIDE;
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) MOZ_OVERRIDE;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;