cc: Calculate "can use lcd text" on the compositor thread

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 54c86604d3435edd63f9d5343787185d09307400..751bd16e5cbb4dc7a7fee7bebc12ec9baa6c8ec4 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -346,6 +346,7 @@ class CC_EXPORT LayerTreeImpl {
   void PushTopControls(const float* top_controls_shown_ratio);
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
+  int last_update_draw_properties_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;
   HeadsUpDisplayLayerImpl* hud_layer_;
   LayerImpl* currently_scrolling_layer_;