cc: Dirty the RenderSurfaceLayerList when taking copy requests.

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index a40a8c72bf6b8140c638207e3b3d00d80b77e4dd..001aa13f146374a52f31b662326925d2adb0f9df 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -573,6 +573,11 @@ void LayerTreeTest::PostCompositeImmediatelyToMainThread() {
                  main_thread_weak_ptr_));
 }
 
+void LayerTreeTest::PostEndTestToMainThread() {
+  main_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&LayerTreeTest::EndTest, main_thread_weak_ptr_));
+}
+
 void LayerTreeTest::WillBeginTest() {
   layer_tree_host_->SetLayerTreeHostClientReady();
 }