CC: Fix missing swap-used-incomplete-tile updates

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 4f092663ee19bbb41197ae08c37177c4d257dba2..17517e65a87ae0ebbee6607a6afdd06c24fc88d4 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -117,6 +117,11 @@ class LayerTreeHostImplForTesting : public LayerTreeHostImpl {
     test_hooks_->SwapBuffersCompleteOnThread(this);
   }
 
+  virtual void UpdateVisibleTiles() OVERRIDE {
+    LayerTreeHostImpl::UpdateVisibleTiles();
+    test_hooks_->UpdateVisibleTilesOnThread(this);
+  }
+
   virtual void NotifyReadyToActivate() OVERRIDE {
     if (block_notify_ready_to_activate_for_testing_)
       notify_ready_to_activate_was_blocked_ = true;