shelf: Allow dragging items from main shelf to overflow shelf.

ash/shelf/shelf_view.h

Index: ash/shelf/shelf_view.h
diff --git a/ash/shelf/shelf_view.h b/ash/shelf/shelf_view.h
index e0692e103249bd6f30ad974826a738540da64d94..05a7c0be3ed3d760a16608eacd12bf3151bf9f1e 100644
--- a/ash/shelf/shelf_view.h
+++ b/ash/shelf/shelf_view.h
@@ -455,8 +455,9 @@ class ASH_EXPORT ShelfView : public views::View,
   // Holds a pointer to main ShelfView when a ShelfView is in overflow mode.
   ShelfView* main_shelf_;
 
-  // True when ripped item from overflow bubble is entered into Shelf.
-  bool dragged_off_from_overflow_to_shelf_;
+  // True when ripped item from overflow bubble is entered into Shelf or vice

[msw, 2017/04/17 19:29:09]

nit: // True when an item is dragged from one shelf to another (eg. overflow).

[sammiequon, 2017/04/17 23:42:29]

Done.

+  // versa.
+  bool dragged_off_from_shelf_to_other_shelf_;

[msw, 2017/04/17 19:29:09]

This name is pretty bad; how about moving this just below |dragged_off_shelf_|
and using the name |dragged_to_another_shelf_| or |dragged_from_another_shelf_|
or similar?

[sammiequon, 2017/04/17 23:42:29]

Done.

 
   // True if the event is a repost event from a event which has just closed the
   // menu of the same shelf item.