Moves maintaining ShellObservers back to Shell

ash/app_list/app_list_presenter_delegate.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 "ash/app_list/app_list_presenter_delegate.h"
 
 #include "ash/common/ash_switches.h"
 #include "ash/common/shelf/app_list_button.h"
 #include "ash/common/shelf/shelf_layout_manager.h"
 #include "ash/common/shelf/shelf_widget.h"
@@ skipping 49 matching lines @@
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListPresenterDelegate, public:
 
 AppListPresenterDelegate::AppListPresenterDelegate(
     app_list::AppListPresenterImpl* presenter,
     app_list::AppListViewDelegateFactory* view_delegate_factory)
     : presenter_(presenter), view_delegate_factory_(view_delegate_factory) {
-  WmShell::Get()->AddShellObserver(this);
+  Shell::GetInstance()->AddShellObserver(this);
 }
 
 AppListPresenterDelegate::~AppListPresenterDelegate() {
   DCHECK(view_);
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)
     keyboard_controller->RemoveObserver(this);
   Shell::GetInstance()->RemovePreTargetHandler(this);
   WmWindow* window = WmWindow::Get(view_->GetWidget()->GetNativeWindow());
   window->GetRootWindowController()->GetShelf()->RemoveObserver(this);
-  WmShell::Get()->RemoveShellObserver(this);
+  Shell::GetInstance()->RemoveShellObserver(this);
 }
 
 app_list::AppListViewDelegate* AppListPresenterDelegate::GetViewDelegate() {
   return view_delegate_factory_->GetDelegate();
 }
 
 void AppListPresenterDelegate::Init(app_list::AppListView* view,
                                     int64_t display_id,
                                     int current_apps_page) {
   // App list needs to know the new shelf layout in order to calculate its
@@ skipping 147 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListPresenterDelegate, WmShelfObserver implementation:
 
 void AppListPresenterDelegate::OnShelfIconPositionsChanged() {
   UpdateBounds();
 }
 
 }  // namespace ash