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

ash/test/shelf_view_test_api.h

Index: ash/test/shelf_view_test_api.h
diff --git a/ash/test/shelf_view_test_api.h b/ash/test/shelf_view_test_api.h
index fbb35c2c1faff89802ce6aed36f187fbfc169222..008442afd9e2fc961e0f4ccd43029ded4d677aa7 100644
--- a/ash/test/shelf_view_test_api.h
+++ b/ash/test/shelf_view_test_api.h
@@ -116,8 +116,9 @@ class ShelfViewTestAPI {
   // Returns true if item is ripped off.
   bool IsRippedOffFromShelf();
 
-  // Returns true if an item is ripped off and entered into shelf.
-  bool DraggedItemFromOverflowToShelf();
+  // Returns true when an item is dragged from one shelf to another (eg.
+  // overflow).
+  bool DraggedItemToAnotherShelf();
 
   // An accessor for |shelf_button_pressed_metric_tracker_|.
   ShelfButtonPressedMetricTracker* shelf_button_pressed_metric_tracker();