Consolidate RenderWidgetHost::CopyFromBackingStore and RenderWidgetHost::AsyncCopyFromBackingStore.

content/browser/renderer_host/test_render_view_host.cc

Index: content/browser/renderer_host/test_render_view_host.cc
diff --git a/content/browser/renderer_host/test_render_view_host.cc b/content/browser/renderer_host/test_render_view_host.cc
index 44423f7a4b8b86f5dabc903415f3164e1d333063..05e82627218b88a06ebed973a2fef1bbe18f74ef 100644
--- a/content/browser/renderer_host/test_render_view_host.cc
+++ b/content/browser/renderer_host/test_render_view_host.cc
@@ -94,13 +94,7 @@ BackingStore* TestRenderWidgetHostView::AllocBackingStore(
   return new TestBackingStore(rwh_, size);
 }
 
-bool TestRenderWidgetHostView::CopyFromCompositingSurface(
-    const gfx::Size& size,
-    skia::PlatformCanvas* output) {
-  return false;
-}
-
-void TestRenderWidgetHostView::AsyncCopyFromCompositingSurface(
+void TestRenderWidgetHostView::CopyFromCompositingSurface(
     const gfx::Size& size,
     skia::PlatformCanvas* output,
     base::Callback<void(bool)> callback) {