mash: Migrate shelf app list button to wm common types

ash/shell/app_list.cc

 // 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.
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/wm_shell.h"
-#include "ash/shell.h"
 #include "ash/shell/example_factory.h"
 #include "ash/shell/toplevel_window.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/string_search.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 274 matching lines @@
 
   void StopSearch() override {
     // Nothing needs to be done.
   }
 
   void ViewInitialized() override {
     // Nothing needs to be done.
   }
 
   void Dismiss() override {
-    DCHECK(Shell::HasInstance());
-    Shell::GetInstance()->DismissAppList();
+    DCHECK(WmShell::HasInstance());
+    WmShell::Get()->DismissAppList();
   }
 
   void ViewClosing() override {
     // Nothing needs to be done.
   }
 
   void OpenHelp() override {
     // Nothing needs to be done.
   }
 
@@ skipping 31 matching lines @@
 };
 
 }  // namespace
 
 app_list::AppListViewDelegate* CreateAppListViewDelegate() {
   return new ExampleAppListViewDelegate;
 }
 
 }  // namespace shell
 }  // namespace ash