Revert 114095 - Move the concept of Activation to the Shell.

chrome/browser/platform_util_aura.cc

 // Copyright (c) 2011 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/platform_util.h"
 
 #include "base/logging.h"
 #include "ui/aura/window.h"
-#include "ui/aura_shell/window_util.h"
 
 namespace platform_util {
 
 gfx::NativeWindow GetTopLevel(gfx::NativeView view) {
   return view->GetToplevelWindow();
 }
 
 gfx::NativeView GetParent(gfx::NativeView view) {
   return view->parent();
 }
 
 bool IsWindowActive(gfx::NativeWindow window) {
-  return aura_shell::IsActiveWindow(window);
+  return window->IsActive();
 }
 
 void ActivateWindow(gfx::NativeWindow window) {
-  aura_shell::ActivateWindow(window);
+  window->Activate();
 }
 
 bool IsVisible(gfx::NativeView view) {
   return view->IsVisible();
 }
 
 }  // namespace platform_util