Move virtual setSurfaceReady to non-virtual StartCompositor.

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 f340974967b51a891c3ed3e6e1516f2ea2aeeae1..769e4deefe1e67f02855e45076c3a4c4672dbd71 100644
--- a/mojo/services/html_viewer/weblayertreeview_impl.cc
+++ b/mojo/services/html_viewer/weblayertreeview_impl.cc
@@ -120,9 +120,6 @@ void WebLayerTreeViewImpl::DidCommitAndDrawFrame() {
 void WebLayerTreeViewImpl::DidCompleteSwapBuffers() {
 }
 
-void WebLayerTreeViewImpl::setSurfaceReady() {
-}
-
 void WebLayerTreeViewImpl::setRootLayer(const blink::WebLayer& layer) {
   layer_tree_host_->SetRootLayer(
       static_cast<const cc_blink::WebLayerImpl*>(&layer)->layer());