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

ui/views/corewm/focus_controller_unittest.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 "ui/views/corewm/focus_controller.h"
 
 #include <map>
 
 #include "ui/aura/client/activation_change_observer.h"
 #include "ui/aura/client/activation_client.h"
@@ skipping 80 matching lines @@
   }
 
  private:
   aura::RootWindow* root_window_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedFocusNotificationObserver);
 };
 
 class ScopedTargetFocusNotificationObserver : public FocusNotificationObserver {
  public:
-  ScopedTargetFocusNotificationObserver(aura::RootWindow* root_window, int id)
+  ScopedTargetFocusNotificationObserver(aura::Window* root_window, int id)
       : target_(root_window->GetChildById(id)) {
     aura::client::SetActivationChangeObserver(target_, this);
     aura::client::SetFocusChangeObserver(target_, this);
     tracker_.Add(target_);
   }
   virtual ~ScopedTargetFocusNotificationObserver() {
     if (tracker_.Contains(target_)) {
       aura::client::SetActivationChangeObserver(target_, NULL);
       aura::client::SetFocusChangeObserver(target_, NULL);
     }
@@ skipping 902 matching lines @@
 DIRECT_FOCUS_CHANGE_TESTS(NoShiftActiveOnActivation);
 
 // Clicking on a window which has capture should not result in a focus change.
 DIRECT_FOCUS_CHANGE_TESTS(NoFocusChangeOnClickOnCaptureWindow);
 
 FOCUS_CONTROLLER_TEST(FocusControllerApiTest,
                       ChangeFocusWhenNothingFocusedAndCaptured);
 
 }  // namespace corewm
 }  // namespace views