DevTools/cc HUD: fix HUD update with threaded compositing

This is a better fix for bug 252664 that also works with threaded
compositing: we request commit on main thread when debug state changes,
then request redraw on impl side once debug state changes get committed.

BUG=252664

Review URL: https://chromiumcodereview.appspot.com/18209004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@210565 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 4e8fc8d..98f8020 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -310,7 +310,7 @@
     return animation_registrar_.get();
   }
 
-  void SetDebugState(const LayerTreeDebugState& debug_state);
+  void SetDebugState(const LayerTreeDebugState& new_debug_state);
   const LayerTreeDebugState& debug_state() const { return debug_state_; }
 
   class CC_EXPORT CullRenderPassesWithCachedTextures {