Removed ScrollingCoordinator and a bunch of composited scrolling'

sky/engine/core/rendering/compositing/GraphicsLayerTreeBuilder.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 65 matching lines @@
             infoForChildren.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->foregroundLayer());
     }
 
     RenderLayerStackingNodeIterator iterator(*layer.stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
     while (RenderLayerStackingNode* curNode = iterator.next())
         rebuild(*curNode->layer(), infoForChildren);
 
     if (hasCompositedLayerMapping) {
         currentCompositedLayerMapping->parentForSublayers()->setChildren(layerChildren);
 
-        // If the layer has a clipping layer the overflow controls layers will be siblings of the clipping layer.
-        // Otherwise, the overflow control layers are normal children.
-        // FIXME: Why isn't this handled in CLM updateInternalHierarchy?
-        if (!currentCompositedLayerMapping->hasClippingLayer() && !currentCompositedLayerMapping->hasScrollingLayer()) {
-            if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForHorizontalScrollbar()) {
-                overflowControlLayer->removeFromParent();
-                currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
-            }
-
-            if (GraphicsLayer* overflowControlLayer = currentCompositedLayerMapping->layerForVerticalScrollbar()) {
-                overflowControlLayer->removeFromParent();
-                currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
-            }
-        }
-
         info.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->childForSuperlayers());
     }
 
     if (layer.scrollParent()
         && layer.scrollParent()->hasCompositedLayerMapping()
         && layer.scrollParent()->compositedLayerMapping()->needsToReparentOverflowControls()
         && layer.scrollParent()->scrollableArea()->topmostScrollChild() == &layer)
         info.childLayersOfEnclosingCompositedLayer->append(layer.scrollParent()->compositedLayerMapping()->detachLayerForOverflowControls(*info.enclosingCompositedLayer));
 }
 
 }