Revert 114283 - Avoid using backing store for compositing layers that just need to clip

Source/WebCore/rendering/RenderLayer.cpp

Index: Source/WebCore/rendering/RenderLayer.cpp
===================================================================
--- Source/WebCore/rendering/RenderLayer.cpp	(revision 115913)
+++ Source/WebCore/rendering/RenderLayer.cpp	(working copy)
@@ -960,19 +960,6 @@
          
     return 0;
 }
-
-RenderLayer* RenderLayer::enclosingCompositingLayerForRepaint(bool includeSelf) const
-{
-    if (includeSelf && isComposited() && !backing()->paintsIntoCompositedAncestor())
-        return const_cast<RenderLayer*>(this);
-
-    for (const RenderLayer* curr = compositingContainer(this); curr; curr = compositingContainer(curr)) {
-        if (curr->isComposited() && !curr->backing()->paintsIntoCompositedAncestor())
-            return const_cast<RenderLayer*>(curr);
-    }
-         
-    return 0;
-}
 #endif
 
 #if ENABLE(CSS_FILTERS)
@@ -2886,7 +2873,7 @@
         // but we need to ensure that we don't cache clip rects computed with the wrong root in this case.
         if (context->updatingControlTints() || (paintBehavior & PaintBehaviorFlattenCompositingLayers))
             paintFlags |= PaintLayerTemporaryClipRects;
-        else if (!backing()->paintsIntoWindow() && !backing()->paintsIntoCompositedAncestor() && !shouldDoSoftwarePaint(this, paintFlags & PaintLayerPaintingReflection)) {
+        else if (!backing()->paintsIntoWindow() && !shouldDoSoftwarePaint(this, paintFlags & PaintLayerPaintingReflection)) {
             // If this RenderLayer should paint into its backing, that will be done via RenderLayerBacking::paintIntoLayer().
             return;
         }