--- a/layout/generic/nsHTMLCanvasFrame.h
+++ b/layout/generic/nsHTMLCanvasFrame.h
@@ -81,17 +81,18 @@ public:
 #ifdef ACCESSIBILITY
   virtual mozilla::a11y::AccType AccessibleType() override;
 #endif
 
   virtual nsIAtom* GetType() const override;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return nsSplittableFrame::IsFrameOfType(aFlags & ~(nsIFrame::eReplaced));
+    return nsSplittableFrame::IsFrameOfType(aFlags &
+      ~(nsIFrame::eReplaced | nsIFrame::eReplacedSizing));
   }
 
 #ifdef DEBUG_FRAME_DUMP
   virtual nsresult GetFrameName(nsAString& aResult) const override;
 #endif
 
   // Inserted child content gets its frames parented by our child block
   virtual nsContainerFrame* GetContentInsertionFrame() override {

--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -2115,16 +2115,21 @@ public:
     eBlockFrame =                       1 << 12,
     eTablePart =                        1 << 13,
     // If this bit is set, the frame doesn't allow ignorable whitespace as
     // children. For example, the whitespace between <table>\n<tr>\n<td>
     // will be excluded during the construction of children. 
     eExcludesIgnorableWhitespace =      1 << 14,
     eSupportsCSSTransforms =            1 << 15,
 
+    // A replaced element that has replaced-element sizing
+    // characteristics (i.e., like images or iframes), as opposed to
+    // inline-block sizing characteristics (like form controls).
+    eReplacedSizing =                   1 << 16,
+
     // These are to allow nsFrame::Init to assert that IsFrameOfType
     // implementations all call the base class method.  They are only
     // meaningful in DEBUG builds.
     eDEBUGAllFrames =                   1 << 30,
     eDEBUGNoFrames =                    1 << 31
   };
 
   /**

--- a/layout/generic/nsImageFrame.h
+++ b/layout/generic/nsImageFrame.h
@@ -107,17 +107,18 @@ public:
 #ifdef ACCESSIBILITY
   virtual mozilla::a11y::AccType AccessibleType() override;
 #endif
 
   virtual nsIAtom* GetType() const override;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return ImageFrameSuper::IsFrameOfType(aFlags & ~(nsIFrame::eReplaced));
+    return ImageFrameSuper::IsFrameOfType(aFlags &
+      ~(nsIFrame::eReplaced | nsIFrame::eReplacedSizing));
   }
 
 #ifdef DEBUG_FRAME_DUMP
   virtual nsresult GetFrameName(nsAString& aResult) const override;
   void List(FILE* out = stderr, const char* aPrefix = "", 
             uint32_t aFlags = 0) const override;
 #endif
 

--- a/layout/generic/nsPluginFrame.h
+++ b/layout/generic/nsPluginFrame.h
@@ -86,17 +86,18 @@ public:
   virtual nsresult  HandleEvent(nsPresContext* aPresContext,
                                 mozilla::WidgetGUIEvent* aEvent,
                                 nsEventStatus* aEventStatus) override;
 
   virtual nsIAtom* GetType() const override;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return nsPluginFrameSuper::IsFrameOfType(aFlags & ~(nsIFrame::eReplaced));
+    return nsPluginFrameSuper::IsFrameOfType(aFlags &
+      ~(nsIFrame::eReplaced | nsIFrame::eReplacedSizing));
   }
 
   virtual bool NeedsView() override { return true; }
 
 #ifdef DEBUG_FRAME_DUMP
   virtual nsresult GetFrameName(nsAString& aResult) const override;
 #endif
 

--- a/layout/generic/nsSubDocumentFrame.h
+++ b/layout/generic/nsSubDocumentFrame.h
@@ -32,17 +32,19 @@ public:
   NS_DECL_QUERYFRAME
 
   virtual nsIAtom* GetType() const override;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
     // nsLeafFrame is already eReplacedContainsBlock, but that's somewhat bogus
     return nsLeafFrame::IsFrameOfType(aFlags &
-      ~(nsIFrame::eReplaced | nsIFrame::eReplacedContainsBlock));
+      ~(nsIFrame::eReplaced |
+        nsIFrame::eReplacedSizing |
+        nsIFrame::eReplacedContainsBlock));
   }
 
   virtual void Init(nsIContent*       aContent,
                     nsContainerFrame* aParent,
                     nsIFrame*         aPrevInFlow) override;
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) override;
 

--- a/layout/generic/nsVideoFrame.h
+++ b/layout/generic/nsVideoFrame.h
@@ -72,17 +72,18 @@ public:
 #ifdef ACCESSIBILITY
   virtual mozilla::a11y::AccType AccessibleType() override;
 #endif
 
   virtual nsIAtom* GetType() const override;
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return nsSplittableFrame::IsFrameOfType(aFlags & ~(nsIFrame::eReplaced));
+    return nsSplittableFrame::IsFrameOfType(aFlags &
+      ~(nsIFrame::eReplaced | nsIFrame::eReplacedSizing));
   }
   
   virtual nsresult CreateAnonymousContent(nsTArray<ContentInfo>& aElements) override;
   virtual void AppendAnonymousContentTo(nsTArray<nsIContent*>& aElements,
                                         uint32_t aFilters) override;
 
   nsIContent* GetPosterImage() { return mPosterImage; }