Provide shared context to Platform API in renderer.

content/renderer/renderer_webkitplatformsupport_impl.h

Index: content/renderer/renderer_webkitplatformsupport_impl.h
diff --git a/content/renderer/renderer_webkitplatformsupport_impl.h b/content/renderer/renderer_webkitplatformsupport_impl.h
index 41100dd99801818144fb617cf3fd5c6a92b3c862..735f7b2876a065b138b362546e575720b7201134 100644
--- a/content/renderer/renderer_webkitplatformsupport_impl.h
+++ b/content/renderer/renderer_webkitplatformsupport_impl.h
@@ -98,6 +98,9 @@ class CONTENT_EXPORT RendererWebKitPlatformSupportImpl
       const WebKit::WebString& locale);
   virtual bool processMemorySizesInBytes(
       size_t* private_bytes, size_t* shared_bytes);
+  virtual WebKit::WebGraphicsContext3D* createOffscreenGraphicsContext3D(
+      const WebKit::WebGraphicsContext3D::Attributes& attributes);
+  virtual WebKit::WebGraphicsContext3D* sharedOffscreenGraphicsContext3D();
 
   // Disables the WebSandboxSupport implementation for testing.
   // Tests that do not set up a full sandbox environment should call
@@ -111,9 +114,6 @@ class CONTENT_EXPORT RendererWebKitPlatformSupportImpl
   // Set WebGamepads to return when sampleGamepads() is invoked.
   static void SetMockGamepadsForTesting(const WebKit::WebGamepads& pads);
 
- protected:
-  virtual GpuChannelHostFactory* GetGpuChannelHostFactory() OVERRIDE;
-
  private:
   bool CheckPreparsedJsCachingEnabled() const;