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

Source/WebCore/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 942 matching lines @@
     if (includeSelf && isComposited())
         return const_cast<RenderLayer*>(this);
 
     for (const RenderLayer* curr = compositingContainer(this); curr; curr = compositingContainer(curr)) {
         if (curr->isComposited())
             return const_cast<RenderLayer*>(curr);
     }
          
     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)
 RenderLayer* RenderLayer::enclosingFilterLayer(bool includeSelf) const
 {
     const RenderLayer* curr = includeSelf ? this : parent();
     for (; curr; curr = curr->parent()) {
         if (curr->requiresFullLayerImageForFilters())
             return const_cast<RenderLayer*>(curr);
     }
@@ skipping 1893 matching lines @@
                         const LayoutRect& paintDirtyRect, PaintBehavior paintBehavior,
                         RenderObject* paintingRoot, RenderRegion* region, OverlapTestRequestMap* overlapTestRequests,
                         PaintLayerFlags paintFlags)
 {
 #if USE(ACCELERATED_COMPOSITING)
     if (isComposited()) {
         // The updatingControlTints() painting pass goes through compositing layers,
         // 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;
         }
     }
 #endif
 
     if (shouldSuppressPaintingLayer(this))
         return;
     
     // If this layer is totally invisible then there is nothing to paint.
@@ skipping 2038 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif