cc: Make scheduling be driven by vsync for android webview.

cc/trees/thread_proxy.cc

Index: cc/trees/thread_proxy.cc
diff --git a/cc/trees/thread_proxy.cc b/cc/trees/thread_proxy.cc
index ff2ca46615e8e2971beeb4b28d791fa6e5dce06c..7c6f0a8fb76e2d7c33c5db52f40a8f8f60800b6c 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -1114,6 +1114,12 @@ DrawResult ThreadProxy::ScheduledActionDrawAndSwapForced() {
   return DrawSwapInternal(forced_draw);
 }
 
+void ThreadProxy::ScheduledActionInvalidateOutputSurface() {
+  TRACE_EVENT0("cc", "ThreadProxy::ScheduledActionInvalidateOutputSurface");
+  DCHECK(impl().layer_tree_host_impl->output_surface());
+  impl().layer_tree_host_impl->output_surface()->Invalidate();
+}
+
 void ThreadProxy::DidAnticipatedDrawTimeChange(base::TimeTicks time) {
   if (impl().current_resource_update_controller)
     impl().current_resource_update_controller->PerformMoreUpdates(time);
@@ -1370,4 +1376,9 @@ void ThreadProxy::DidCompletePageScaleAnimationOnImplThread() {
                             main_thread_weak_ptr_));
 }
 
+void ThreadProxy::OnDrawForOutputSurface() {
+  DCHECK(IsImplThread());
+  impl().scheduler->OnDrawForOutputSurface();
+}
+
 }  // namespace cc