Implement will-change-based GPU rasterization hint

Source/platform/graphics/GraphicsLayer.h

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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 187 matching lines @@
 
     float opacity() const { return m_opacity; }
     void setOpacity(float);
 
     blink::WebBlendMode blendMode() const { return m_blendMode; }
     void setBlendMode(blink::WebBlendMode);
 
     bool isRootForIsolatedGroup() const { return m_isRootForIsolatedGroup; }
     void setIsRootForIsolatedGroup(bool);
 
+    bool hasGpuRasterizationHint() const { return m_hasGpuRasterizationHint; }
+    void setHasGpuRasterizationHint(bool);
+
     const FilterOperations& filters() const { return m_filters; }
 
     // Returns true if filter can be rendered by the compositor
     bool setFilters(const FilterOperations&);
     void setBackgroundFilters(const FilterOperations&);
 
     // Some GraphicsLayers paint only the foreground or the background content
     GraphicsLayerPaintingPhase paintingPhase() const { return m_paintingPhase; }
     void setPaintingPhase(GraphicsLayerPaintingPhase phase) { m_paintingPhase = phase; }
 
@@ skipping 134 matching lines @@
 
     FilterOperations m_filters;
 
     bool m_contentsOpaque : 1;
     bool m_shouldFlattenTransform: 1;
     bool m_backfaceVisibility : 1;
     bool m_masksToBounds : 1;
     bool m_drawsContent : 1;
     bool m_contentsVisible : 1;
     bool m_isRootForIsolatedGroup : 1;
+    bool m_hasGpuRasterizationHint: 1;
 
     bool m_hasScrollParent : 1;
     bool m_hasClipParent : 1;
 
     GraphicsLayerPaintingPhase m_paintingPhase;
     CompositingCoordinatesOrientation m_contentsOrientation; // affects orientation of layer contents
 
     Vector<GraphicsLayer*> m_children;
     GraphicsLayer* m_parent;
 
@@ skipping 29 matching lines @@
 };
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void PLATFORM_EXPORT showGraphicsLayerTree(const WebCore::GraphicsLayer*);
 #endif
 
 #endif // GraphicsLayer_h