[#4] Pass gfx structs by const ref (gfx::PointF)

cc/trees/layer_tree_host_common.h

Index: cc/trees/layer_tree_host_common.h
diff --git a/cc/trees/layer_tree_host_common.h b/cc/trees/layer_tree_host_common.h
index a15f9c0040356c7bb89747091413c73fc8ab8013..d639afdb3760c517808f5cad3ddb109924062ee5 100644
--- a/cc/trees/layer_tree_host_common.h
+++ b/cc/trees/layer_tree_host_common.h
@@ -97,15 +97,16 @@ class CC_EXPORT LayerTreeHostCommon {
 
   // Performs hit testing for a given render_surface_layer_list.
   static LayerImpl* FindLayerThatIsHitByPoint(
-      gfx::PointF screen_space_point,
+      const gfx::PointF& screen_space_point,
       const LayerImplList& render_surface_layer_list);
 
   static LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
-      gfx::PointF screen_space_point,
+      const gfx::PointF& screen_space_point,
       const LayerImplList& render_surface_layer_list);
 
-  static bool LayerHasTouchEventHandlersAt(gfx::PointF screen_space_point,
-                                           LayerImpl* layer_impl);
+  static bool LayerHasTouchEventHandlersAt(
+      const gfx::PointF& screen_space_point,
+      LayerImpl* layer_impl);
 
   template <typename LayerType>
   static bool RenderSurfaceContributesToTarget(LayerType*,