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

ash/metrics/user_metrics_recorder_unittest.cc

 // 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.
 
 #include "ash/metrics/user_metrics_recorder.h"
 
 #include <memory>
 
-#include "ash/shelf/shelf_model.h"
+#include "ash/common/shelf/shelf_model.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shell.h"
 #include "ash/system/user/login_status.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/test_shelf_delegate.h"
 #include "ash/test/test_system_tray_delegate.h"
 #include "ash/test/user_metrics_recorder_test_api.h"
 #include "base/test/histogram_tester.h"
 #include "ui/aura/window.h"
 
@@ skipping 195 matching lines @@
   aura::Window* unpinned_window_5 = CreateTestWindow();
   test_shelf_delegate->AddShelfItem(unpinned_window_5);
 
   user_metrics_recorder_test_api()->RecordPeriodicMetrics();
   histograms().ExpectBucketCount(kAsh_Shelf_NumberOfItems, 5, 1);
   histograms().ExpectBucketCount(kAsh_Shelf_NumberOfPinnedItems, 2, 1);
   histograms().ExpectBucketCount(kAsh_Shelf_NumberOfUnpinnedItems, 3, 1);
 }
 
 }  // namespace ash