Bug 1022612. Part 23: Remove nsDisplayItem::IsVaryingRelativeToMovingFrame. r=mattwoodrow

It's obsolete and no-one calls it.

--HG--
extra : rebase_source : 588144666e7abac06c19bfa5d1d3f41589bdd988

layout/base/nsDisplayList.cpp

@@ -2252,23 +2252,6 @@ nsDisplayBackgroundImage::IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aCo
   return false;
 }
 
-bool
-nsDisplayBackgroundImage::IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                         nsIFrame* aFrame)
-{
-  if (!mBackgroundStyle)
-    return false;
-  if (!mBackgroundStyle->HasFixedBackground())
-    return false;
-
-  // If aFrame is mFrame or an ancestor in this document, and aFrame is
-  // not the viewport frame, then moving aFrame will move mFrame
-  // relative to the viewport, so our fixed-pos background will change.
-  return aFrame->GetParent() &&
-    (aFrame == mFrame ||
-     nsLayoutUtils::IsProperAncestorFrame(aFrame, mFrame));
-}
-
 nsRect
 nsDisplayBackgroundImage::GetPositioningArea()
 {
@@ -3125,13 +3108,6 @@ bool nsDisplayWrapList::IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColo
   return false;
 }
 
-bool nsDisplayWrapList::IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                         nsIFrame* aFrame) {
-  NS_WARNING("nsDisplayWrapList::IsVaryingRelativeToMovingFrame called unexpectedly");
-  // We could try to do something but let's conservatively just return true.
-  return true;
-}
-
 void nsDisplayWrapList::Paint(nsDisplayListBuilder* aBuilder,
                               nsRenderingContext* aCtx) {
   NS_ERROR("nsDisplayWrapList should have been flattened away for painting");

layout/base/nsDisplayList.h

@@ -1101,16 +1101,6 @@ public:
    * bounds with the same (possibly translucent) color
    */
   virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) { return false; }
-  /**
-   * @return false if the painting performed by the item is invariant
-   * when the item's underlying frame is moved relative to aFrame.
-   * In other words, if you render the item at locations P and P', the rendering
-   * only differs by the translation.
-   * It return true for all wrapped lists.
-   */
-  virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                nsIFrame* aFrame)
-  { return false; }
   /**
    * @return true if the contents of this item are rendered fixed relative
    * to the nearest viewport.
@@ -2191,8 +2181,6 @@ public:
                                    const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
   virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
                                    bool* aSnap) MOZ_OVERRIDE;
-  virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                nsIFrame* aFrame) MOZ_OVERRIDE;
   virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE;
   /**
    * GetBounds() returns the background painting area.
@@ -2607,8 +2595,6 @@ public:
   virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
                                    bool* aSnap) MOZ_OVERRIDE;
   virtual bool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) MOZ_OVERRIDE;
-  virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                nsIFrame* aFrame) MOZ_OVERRIDE;
   virtual void Paint(nsDisplayListBuilder* aBuilder, nsRenderingContext* aCtx) MOZ_OVERRIDE;
   virtual bool ComputeVisibility(nsDisplayListBuilder* aBuilder,
                                  nsRegion* aVisibleRegion,

layout/tables/nsTableFrame.cpp

@@ -1088,20 +1088,6 @@ nsDisplayTableItem::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
   return mFrame->GetVisualOverflowRectRelativeToSelf() + ToReferenceFrame();
 }
 
-bool
-nsDisplayTableItem::IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                   nsIFrame* aFrame)
-{
-  if (!mPartHasFixedBackground)
-    return false;
-
-  // If aFrame is mFrame or an ancestor in this document, and aFrame is
-  // not the viewport frame, then moving aFrame will move mFrame
-  // relative to the viewport, so our fixed-pos background will change.
-  return mFrame == aFrame ||
-    nsLayoutUtils::IsProperAncestorFrame(aFrame, mFrame);
-}
-
 /* static */ void
 nsDisplayTableItem::UpdateForFrameBackground(nsIFrame* aFrame)
 {

layout/tables/nsTableFrame.h

@@ -50,8 +50,6 @@ public:
       nsDisplayItem(aBuilder, aFrame),
       mPartHasFixedBackground(false) {}
 
-  virtual bool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
-                                                nsIFrame* aFrame) MOZ_OVERRIDE;
   // With collapsed borders, parts of the collapsed border can extend outside
   // the table part frames, so allow this display element to blow out to our
   // overflow rect. This is also useful for row frames that have spanning