Bug 810470. Part 5: Remove more unused code. r=mattwoodrow

--HG--
extra : rebase_source : c8f0d038a37d8fa9e581d83bfe6ea7bc10bd0eef

layout/base/nsCSSRendering.cpp

@@ -2926,8 +2926,6 @@ nsCSSRendering::PrepareBackgroundLayer(nsPresContext* aPresContext,
   // of aForFrame's border-box will be rendered)
   nsPoint imageTopLeft;
   if (NS_STYLE_BG_ATTACHMENT_FIXED == aLayer.mAttachment) {
-    aPresContext->SetHasFixedBackgroundFrame();
-
     if ((aFlags & nsCSSRendering::PAINTBG_TO_WINDOW) &&
         !IsTransformed(aForFrame, attachedToFrame)) {
       // Clip background-attachment:fixed backgrounds to the viewport, if we're

layout/base/nsPresContext.h

@@ -939,9 +939,6 @@ public:
     PropertyTable()->DeleteAllFor(aFrame);
   }
 
-  bool MayHaveFixedBackgroundFrames() { return mMayHaveFixedBackgroundFrames; }
-  void SetHasFixedBackgroundFrame() { mMayHaveFixedBackgroundFrames = true; }
-
   virtual size_t SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const;
   virtual size_t SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf) const {
     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
@@ -1221,7 +1218,6 @@ protected:
   unsigned              mPendingUIResolutionChanged : 1;
   unsigned              mPendingMediaFeatureValuesChanged : 1;
   unsigned              mPrefChangePendingNeedsReflow : 1;
-  unsigned              mMayHaveFixedBackgroundFrames : 1;
   // True if the requests in mInvalidateRequestsSinceLastPaint cover the
   // entire viewport
   unsigned              mAllInvalidated : 1;