mash: Move shelf model and item classes to ash/common/shelf

ash/shelf/shelf_button_pressed_metric_tracker.h

 // Copyright 2015 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_BUTTON_PRESSED_METRIC_TRACKER_H_
 #define ASH_SHELF_SHELF_BUTTON_PRESSED_METRIC_TRACKER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
-#include "ash/shelf/shelf_item_delegate.h"
+#include "ash/common/shelf/shelf_item_delegate.h"
 #include "base/macros.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
 #include "ui/events/event.h"
 
 namespace views {
 class Button;
 }  // namespace views
 
 namespace ash {
@@ skipping 61 matching lines @@
   // Stores the source button of the last window minimize action.
   // NOTE: This may become stale and should not be operated on. Not owned.
   const views::Button* last_minimized_source_button_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfButtonPressedMetricTracker);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_BUTTON_PRESSED_METRIC_TRACKER_H_