cc: add layer usage hint to texture layer

webkit/compositor_bindings/web_external_texture_layer_impl.h

 // Copyright 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 WebExternalTextureLayerImpl_h
 #define WebExternalTextureLayerImpl_h
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/texture_layer_client.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebExternalTextureLayer.h"
 #include "webkit/compositor_bindings/webkit_compositor_bindings_export.h"
 
 namespace WebKit {
 
 class WebLayerImpl;
 struct WebFloatRect;
 
 class WebExternalTextureLayerImpl : public WebExternalTextureLayer,
                                     public cc::TextureLayerClient {
  public:
   WEBKIT_COMPOSITOR_BINDINGS_EXPORT explicit WebExternalTextureLayerImpl(
-      WebExternalTextureLayerClient*);
+      WebExternalTextureLayerClient*, bool single_buffer);
   virtual ~WebExternalTextureLayerImpl();
 
   // WebExternalTextureLayer implementation.
   virtual WebLayer* layer();
   virtual void setTextureId(unsigned);
   virtual void setFlipped(bool);
   virtual void setUVRect(const WebFloatRect&);
   virtual void setOpaque(bool);
   virtual void setPremultipliedAlpha(bool);
   virtual void willModifyTexture();
   virtual void setRateLimitContext(bool);
 
   // TextureLayerClient implementation.
   virtual unsigned prepareTexture(cc::ResourceUpdateQueue&) OVERRIDE;
   virtual WebGraphicsContext3D* context() OVERRIDE;
 
  private:
   WebExternalTextureLayerClient* client_;
   scoped_ptr<WebLayerImpl> layer_;
 };
 
 }
 
 #endif  // WebExternalTextureLayerImpl_h