Add RootWindowController

ash/wm/window_util.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/wm/window_util.h"
 
 #include "ash/shell.h"
 #include "ash/wm/activation_controller.h"
 #include "ash/wm/window_properties.h"
 #include "ui/aura/client/activation_client.h"
@@ skipping 81 matching lines @@
 void RestoreWindow(aura::Window* window) {
   window->SetProperty(aura::client::kShowStateKey, ui::SHOW_STATE_NORMAL);
 }
 
 void CenterWindow(aura::Window* window) {
   const gfx::Display display = gfx::Screen::GetMonitorNearestWindow(window);
   gfx::Rect center = display.work_area().Center(window->bounds().size());
   window->SetBounds(center);
 }
 
+internal::RootWindowController* GetRootWindowController(
+    aura::RootWindow* root_window) {
+  return root_window->GetProperty(internal::kRootWindowControllerKey);
+}
+
 }  // namespace wm
 }  // namespace ash