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 a1bac0e0e6445c2d3bb0e05c87411d480196aec9..59d3c3706ec51a44610932959f2ad36dafaa3117 100644
--- a/cc/output/delegating_renderer.h
+++ b/cc/output/delegating_renderer.h
@@ -15,10 +15,8 @@ namespace cc {
 class OutputSurface;
 class ResourceProvider;
 
-class CC_EXPORT DelegatingRenderer
-    : public Renderer,
-      public NON_EXPORTED_BASE(
-          WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback) {
+class CC_EXPORT DelegatingRenderer :
+    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,