Enable accelerated compositing of web pages when using webkit compositor

ui/gfx/compositor/compositor.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_COMPOSITOR_COMPOSITOR_H_
 #define UI_GFX_COMPOSITOR_COMPOSITOR_H_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "ui/gfx/compositor/compositor_export.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 
 class SkCanvas;
 namespace gfx {
 class Point;
 class Rect;
 }
 
 namespace ui {
 
 class CompositorObserver;
 class Layer;
 
+class SharedResources {
+ public:
+  virtual ~SharedResources() {}
+  virtual bool MakeSharedContextCurrent() = 0;
+};
+
 struct TextureDrawParams {
   TextureDrawParams();
 
   // The transform to be applied to the texture.
   ui::Transform transform;
 
   // If this is true, then the texture is blended with the pixels behind it.
   // Otherwise, the drawn pixels clobber the old pixels.
   bool blend;
 
@@ skipping 147 matching lines @@
   // calls to it.
   static ui::Compositor*(*compositor_factory_)(
       ui::CompositorDelegate* delegate);
 
   friend class base::RefCounted<Compositor>;
 };
 
 }  // namespace ui
 
 #endif  // UI_GFX_COMPOSITOR_COMPOSITOR_H_