Move context-related callbacks into OutputSurface

cc/output/delegating_renderer.h

Index: cc/output/delegating_renderer.h
diff --git a/cc/output/delegating_renderer.h b/cc/output/delegating_renderer.h
index 590cf4f4f1b3771653c865d00cd4236b501ce915..99da649572e5566a08058b4869cd97b9cae2f471 100644
--- a/cc/output/delegating_renderer.h
+++ b/cc/output/delegating_renderer.h
@@ -16,9 +16,7 @@ class OutputSurface;
 class ResourceProvider;
 
 class CC_EXPORT DelegatingRenderer :
-    public Renderer,
-    public NON_EXPORTED_BASE(
-        WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback) {
+    public Renderer {
  public:
   static scoped_ptr<DelegatingRenderer> Create(
       RendererClient* client,
@@ -46,9 +44,6 @@ class CC_EXPORT DelegatingRenderer :
                                       size_t bytes_visible_and_nearby,
                                       size_t bytes_allocated) OVERRIDE {}
 
-  // WebGraphicsContext3D::WebGraphicsContextLostCallback implementation.
-  virtual void onContextLost() OVERRIDE;
-
  private:
   DelegatingRenderer(RendererClient* client,
                      OutputSurface* output_surface,