Touchpad scroll latching enabled for Mac behind flag.

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 6af8dd9f00fc8e75b34a4f4b0f68ad32a8dcf950..1776f3ee3d5e1a345c1aaf04667ad75897406a6c 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -609,6 +609,8 @@ class CC_EXPORT LayerTreeHostImpl
   void SetLayerTreeMutator(std::unique_ptr<LayerTreeMutator> mutator);
   LayerTreeMutator* mutator() { return mutator_.get(); }
 
+  void ClearCurrentlyScrollingLayer();

[ericrk, 2016/08/25 16:56:50]

If this is only made public for testing, can you leave this function private and
add a "ClearCurrentlyScrollingLayerForTesting"?

[sahel, 2016/08/25 19:32:57]

Done.

+
  protected:
   LayerTreeHostImpl(
       const LayerTreeSettings& settings,
@@ -684,8 +686,6 @@ class CC_EXPORT LayerTreeHostImpl
   // the frame should be drawn.
   DrawResult CalculateRenderPasses(FrameData* frame);
 
-  void ClearCurrentlyScrollingLayer();
-
   void HandleMouseOverScrollbar(LayerImpl* layer_impl);
 
   LayerImpl* FindScrollLayerForDeviceViewportPoint(