chromeos: Rename ash::WmShelf to Shelf

ash/system/date/tray_system_info.cc

 // Copyright 2016 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/system/date/tray_system_info.h"
 
-#include "ash/shelf/wm_shelf.h"
+#include "ash/shelf/shelf.h"
 #include "ash/shell.h"
 #include "ash/system/date/date_view.h"
 #include "ash/system/date/system_info_default_view.h"
 #include "ash/system/system_clock_observer.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/tray/tray_item_view.h"
 
 namespace ash {
 
@@ skipping 86 matching lines @@
 }
 
 void TraySystemInfo::UpdateTimeFormat() {
   if (tray_view_)
     tray_view_->UpdateTimeFormat();
   if (default_view_)
     default_view_->GetDateView()->UpdateTimeFormat();
 }
 
 }  // namespace ash