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

cc/trees/layer_tree_host_unittest.cc

Index: cc/trees/layer_tree_host_unittest.cc
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index c2f34174130e6f487716f14872a3764e97f0615b..00f4f9aa68dd1d46012a5698aeda07456d3ae923 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -2707,10 +2707,26 @@ class LayerTreeHostTestAbortedCommitDoesntStall : public LayerTreeHostTest {
 
 class LayerTreeHostTestAbortedCommitDoesntStallSynchronousCompositor
     : public LayerTreeHostTestAbortedCommitDoesntStall {
+ protected:
   void InitializeSettings(LayerTreeSettings* settings) override {
     LayerTreeHostTestAbortedCommitDoesntStall::InitializeSettings(settings);
     settings->using_synchronous_renderer_compositor = true;
   }
+
+  void ScheduledActionInvalidateOutputSurface() override {
+    ImplThreadTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(
+            &LayerTreeHostTestAbortedCommitDoesntStallSynchronousCompositor::
+                CallOnDraw,
+            base::Unretained(this)));
+  }
+
+  void CallOnDraw() {
+    // Synchronous compositor does not draw unless told to do so by the output
+    // surface.
+    output_surface()->client()->OnDraw();
+  }
 };
 
 MULTI_THREAD_TEST_F(