Changed Blimp client to start with white screen before drawing contents

cc/trees/remote_channel_impl.cc

Index: cc/trees/remote_channel_impl.cc
diff --git a/cc/trees/remote_channel_impl.cc b/cc/trees/remote_channel_impl.cc
index bacfa617039f86f4cb30adf269d91075811d685b..42d943d32a7c1047f76abfe20e1e728e86de1476 100644
--- a/cc/trees/remote_channel_impl.cc
+++ b/cc/trees/remote_channel_impl.cc
@@ -331,7 +331,12 @@ bool RemoteChannelImpl::MainFrameWillHappenForTesting() {
   return main_frame_will_happen;
 }
 
-void RemoteChannelImpl::DidCompleteSwapBuffers() {}
+void RemoteChannelImpl::DidCompleteSwapBuffers() {
+  DCHECK(task_runner_provider_->IsImplThread());
+  MainThreadTaskRunner()->PostTask(
+      FROM_HERE, base::Bind(&RemoteChannelImpl::DidCompleteSwapBuffersOnMain,
+                            impl().remote_channel_weak_ptr));
+}
 
 void RemoteChannelImpl::SetRendererCapabilitiesMainCopy(
     const RendererCapabilities& capabilities) {}
@@ -398,6 +403,11 @@ void RemoteChannelImpl::SendMessageProto(
                  impl().remote_channel_weak_ptr, base::Passed(&proto)));
 }
 
+void RemoteChannelImpl::DidCompleteSwapBuffersOnMain() {
+  DCHECK(task_runner_provider_->IsMainThread());
+  main().layer_tree_host->DidCompleteSwapBuffers();
+}
+
 void RemoteChannelImpl::DidLoseOutputSurfaceOnMain() {
   DCHECK(task_runner_provider_->IsMainThread());