Make cc output surface creation async

mojo/services/html_viewer/weblayertreeview_impl.cc

Index: mojo/services/html_viewer/weblayertreeview_impl.cc
diff --git a/mojo/services/html_viewer/weblayertreeview_impl.cc b/mojo/services/html_viewer/weblayertreeview_impl.cc
index 3f8ff804255125e530b9d44007e6e768965ff531..e3b56a8636eb730df833d2ea24f32ff85b37878d 100644
--- a/mojo/services/html_viewer/weblayertreeview_impl.cc
+++ b/mojo/services/html_viewer/weblayertreeview_impl.cc
@@ -79,9 +79,8 @@ void WebLayerTreeViewImpl::ApplyViewportDeltas(
   widget_->applyViewportDeltas(scroll_delta, page_scale, top_controls_delta);
 }
 
-scoped_ptr<cc::OutputSurface> WebLayerTreeViewImpl::CreateOutputSurface(
-    bool fallback) {
-  return output_surface_.Pass();
+void WebLayerTreeViewImpl::RequestNewOutputSurface(bool fallback) {
+  layer_tree_host_->SetOutputSurface(output_surface_.Pass());
 }
 
 void WebLayerTreeViewImpl::DidInitializeOutputSurface() {