mash: remove more shell/shelf WmWindow usage.

ash/shelf/wm_shelf.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/shelf/wm_shelf.h"
 
 #include "ash/public/cpp/config.h"
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
@@ skipping 55 matching lines @@
 WmShelf::WmShelf() : shelf_locking_manager_(this) {
   // TODO: ShelfBezelEventHandler needs to work with mus too.
   // http://crbug.com/636647
   if (Shell::GetAshConfig() != Config::MASH)
     bezel_event_handler_ = base::MakeUnique<ShelfBezelEventHandler>(this);
 }
 
 WmShelf::~WmShelf() {}
 
 // static
-WmShelf* WmShelf::ForWindow(WmWindow* window) {
-  return window->GetRootWindowController()->GetShelf();
+WmShelf* WmShelf::ForWindow(aura::Window* window) {
+  return GetRootWindowController(window->GetRootWindow())->GetShelf();
 }
 
 // static
 bool WmShelf::CanChangeShelfAlignment() {
   if (Shell::Get()->session_controller()->IsUserSupervised())
     return false;
 
   const LoginStatus login_status =
       Shell::Get()->session_controller()->login_status();
 
@@ skipping 267 matching lines @@
 
 void WmShelf::OnBackgroundUpdated(ShelfBackgroundType background_type,
                                   AnimationChangeType change_type) {
   if (background_type == GetBackgroundType())
     return;
   for (auto& observer : observers_)
     observer.OnBackgroundTypeChanged(background_type, change_type);
 }
 
 }  // namespace ash