Remove the HasOwnBackingButPaintsIntoAncestor compositing state.

Source/core/rendering/compositing/GraphicsLayerUpdater.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 79 matching lines @@
 
 void GraphicsLayerUpdater::updateRecursive(RenderLayer& layer, UpdateType updateType, const UpdateContext& context, Vector<RenderLayer*>& layersNeedingPaintInvalidation)
 {
     if (layer.hasCompositedLayerMapping()) {
         CompositedLayerMapping* mapping = layer.compositedLayerMapping();
 
         if (updateType == ForceUpdate || mapping->needsGraphicsLayerUpdate()) {
             const RenderLayer* compositingContainer = context.compositingContainer(layer);
             ASSERT(compositingContainer == layer.enclosingLayerWithCompositedLayerMapping(ExcludeSelf));
 
-            if (mapping->updateRequiresOwnBackingStoreForAncestorReasons(compositingContainer)) {
-                TRACE_LAYER_INVALIDATION(&layer, InspectorLayerInvalidationTrackingEvent::AncestorRequiresNewLayer);
-                layersNeedingPaintInvalidation.append(&layer);
-                updateType = ForceUpdate;
-            }
-
             if (mapping->updateGraphicsLayerConfiguration())
                 m_needsRebuildTree = true;
 
             mapping->updateGraphicsLayerGeometry(compositingContainer, context.compositingStackingContext(), layersNeedingPaintInvalidation);
 
             if (mapping->hasUnpositionedOverflowControlsLayers())
                 layer.scrollableArea()->positionOverflowControls(IntSize());
 
             updateType = mapping->updateTypeForChildren(updateType);
             mapping->clearNeedsGraphicsLayerUpdate();
@@ skipping 12 matching lines @@
     if (layer.hasCompositedLayerMapping())
         layer.compositedLayerMapping()->assertNeedsToUpdateGraphicsLayerBitsCleared();
 
     for (RenderLayer* child = layer.firstChild(); child; child = child->nextSibling())
         assertNeedsToUpdateGraphicsLayerBitsCleared(*child);
 }
 
 #endif
 
 } // namespace blink