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

ash/shelf/shelf_view.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_SHELF_SHELF_VIEW_H_
 #define ASH_SHELF_SHELF_VIEW_H_
 
 #include <memory>
 #include <string>
 #include <utility>
@@ skipping 212 matching lines @@
   // Fades |view| from an opacity of 0 to 1. This is when adding a new item.
   void FadeIn(views::View* view);
 
   // Invoked when the pointer has moved enough to trigger a drag. Sets
   // internal state in preparation for the drag.
   void PrepareForDrag(Pointer pointer, const ui::LocatedEvent& event);
 
   // Invoked when the mouse is dragged. Updates the models as appropriate.
   void ContinueDrag(const ui::LocatedEvent& event);
 
+  // Ends the drag on the other shelf. (ie if we are on main shelf, ends drag on
+  // the overflow shelf). Invoked when a shelf item is being dragged from one
+  // shelf to the other.
+  void EndDragOnOtherShelf(bool cancel);
+
   // Handles ripping off an item from the shelf. Returns true when the item got
   // removed.
   bool HandleRipOffDrag(const ui::LocatedEvent& event);
 
   // Finalize the rip off dragging by either |cancel| the action or validating.
   void FinalizeRipOffDrag(bool cancel);
 
   // Check if an item can be ripped off or not.
   RemovableState RemovableByRipOff(int index) const;
 
@@ skipping 196 matching lines @@
 
   // The cursor offset to the middle of the dragged item.
   gfx::Vector2d drag_image_offset_;
 
   // The view which gets replaced by our drag icon proxy.
   views::View* drag_replaced_view_ = nullptr;
 
   // True when the icon was dragged off the shelf.
   bool dragged_off_shelf_ = false;
 
+  // True when an item is dragged from one shelf to another (eg. overflow).
+  bool dragged_to_another_shelf_ = false;
+
   // The rip off view when a snap back operation is underway.
   views::View* snap_back_from_rip_off_view_ = nullptr;
 
   // True when this ShelfView is used for Overflow Bubble.
   bool overflow_mode_ = false;
 
   // Holds a pointer to main ShelfView when a ShelfView is in overflow mode.
   ShelfView* main_shelf_ = nullptr;
 
   // True when ripped item from overflow bubble is entered into Shelf.
@@ skipping 12 matching lines @@
   ShelfButtonPressedMetricTracker shelf_button_pressed_metric_tracker_;
 
   base::WeakPtrFactory<ShelfView> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_VIEW_H_