Fix the bug that negative outline-offset is covered up by composited

third_party/WebKit/Source/platform/graphics/GraphicsLayerClient.h

 /*
  * Copyright (C) 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 25 matching lines @@
 class GraphicsLayer;
 class IntRect;
 
 enum GraphicsLayerPaintingPhaseFlags {
   GraphicsLayerPaintBackground = (1 << 0),
   GraphicsLayerPaintForeground = (1 << 1),
   GraphicsLayerPaintMask = (1 << 2),
   GraphicsLayerPaintOverflowContents = (1 << 3),
   GraphicsLayerPaintCompositedScroll = (1 << 4),
   GraphicsLayerPaintChildClippingMask = (1 << 5),
+  GraphicsLayerPaintDecoration = (1 << 6),
   GraphicsLayerPaintAllWithOverflowClip =
       (GraphicsLayerPaintBackground | GraphicsLayerPaintForeground |
        GraphicsLayerPaintMask)
 };
 typedef unsigned GraphicsLayerPaintingPhase;
 
 enum {
   LayerTreeNormal = 0,
   // Dump extra debugging info like layer addresses.
   LayerTreeIncludesDebugInfo = 1 << 0,
@@ skipping 39 matching lines @@
   // This is executed in GraphicsLayer construction and destruction
   // to verify that we don't create or destroy GraphicsLayers
   // while painting.
   virtual void verifyNotPainting() {}
 #endif
 };
 
 }  // namespace blink
 
 #endif  // GraphicsLayerClient_h