Hit test on the layer tree rather than the RSLL

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 4330213e2e18ccb9d3be16e0bb3bb470fc68a618..5b740c387c6be5eac3cae33038e124ea2567ea5c 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -252,6 +252,14 @@ class CC_EXPORT LayerTreeImpl {
     return render_surface_layer_list_id_;
   }
 
+  LayerImpl* FindFirstScrollingLayerThatIsHitByPoint(
+      const gfx::PointF& screen_space_point);
+
+  LayerImpl* FindLayerThatIsHitByPoint(const gfx::PointF& screen_space_point);
+
+  LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
+      const gfx::PointF& screen_space_point);
+
  protected:
   explicit LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
   void ReleaseResourcesRecursive(LayerImpl* current);