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

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index e66a3906e17db7d3124377331a65b3a661aa3ad5..b01717a3238ab42ad9504c38d123b3864744a650 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1430,6 +1430,10 @@ void LayerTreeHostImpl::ReclaimResources(const CompositorFrameAck* ack) {
   }
 }
 
+void LayerTreeHostImpl::OnDraw() {
+  client_->OnDrawForOutputSurface();
+}
+
 void LayerTreeHostImpl::OnCanDrawStateChangedForTree() {
   client_->OnCanDrawStateChanged(CanDraw());
 }