Make GetRootWindow() return a Window instead of a RootWindow.

chrome/browser/ui/ash/launcher/browser_status_monitor.cc

 // Copyright 2013 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 "chrome/browser/ui/ash/launcher/browser_status_monitor.h"
 
 #include "ash/shell.h"
 #include "ash/wm/window_util.h"
 #include "base/stl_util.h"
 #include "chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h"
@@ skipping 165 matching lines @@
   UpdateBrowserItemState();
 }
 
 void BrowserStatusMonitor::OnDisplayBoundsChanged(
     const gfx::Display& display) {
   // Do nothing here.
 }
 
 void BrowserStatusMonitor::OnDisplayAdded(const gfx::Display& new_display) {
   // Add a new RootWindow and its ActivationClient to observed list.
-  aura::RootWindow* root_window = ash::Shell::GetInstance()->
+  aura::Window* root_window = ash::Shell::GetInstance()->
       display_controller()->GetRootWindowForDisplayId(new_display.id());
   // When the primary root window's display get removed, the existing root
   // window is taken over by the new display and the observer is already set.
   if (!observed_root_windows_.IsObserving(root_window)) {
     observed_root_windows_.Add(static_cast<aura::Window*>(root_window));
     observed_activation_clients_.Add(
         aura::client::GetActivationClient(root_window));
   }
 }
 
@@ skipping 84 matching lines @@
   }
 }
 
 void BrowserStatusMonitor::RemoveWebContentsObserver(
     content::WebContents* contents) {
   DCHECK(webcontents_to_observer_map_.find(contents) !=
       webcontents_to_observer_map_.end());
   delete webcontents_to_observer_map_[contents];
   webcontents_to_observer_map_.erase(contents);
 }