Second attempt at moving the StackingClient to a property on the RootWindow.

ui/aura/test/aura_test_base.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 "ui/aura/test/aura_test_base.h"
 
 #if defined(OS_WIN)
 #include <ole2.h>
 #endif
 
 #include "ui/aura/root_window.h"
-#include "ui/aura/test/test_stacking_client.h"
 
 namespace aura {
 namespace test {
 
 AuraTestBase::AuraTestBase()
     : setup_called_(false),
       teardown_called_(false) {
 #if defined(OS_WIN)
   OleInitialize(NULL);
 #endif
 
-  // TestStackingClient is owned by the root window.
-  new TestStackingClient();
   RootWindow::GetInstance()->Show();
   RootWindow::GetInstance()->SetHostSize(gfx::Size(600, 600));
 }
 
 AuraTestBase::~AuraTestBase() {
 #if defined(OS_WIN)
   OleUninitialize();
 #endif
   CHECK(setup_called_)
       << "You have overridden SetUp but never called super class's SetUp";
   CHECK(teardown_called_)
       << "You have overridden TearDown but never called super class's TearDown";
 
   // Flush the message loop because we have pending release tasks
   // and these tasks if un-executed would upset Valgrind.
   RunAllPendingInMessageLoop();
 
   // Ensure that we don't use the previously-allocated static RootWindow object
   // later -- on Linux, it holds a reference to our message loop's X connection.
   aura::RootWindow::DeleteInstance();
 }
 
-TestStackingClient* AuraTestBase::GetTestStackingClient() {
-  return static_cast<TestStackingClient*>(
-      aura::RootWindow::GetInstance()->stacking_client());
-}
-
 void AuraTestBase::SetUp() {
   testing::Test::SetUp();
   setup_called_ = true;
 }
 
 void AuraTestBase::TearDown() {
   teardown_called_ = true;
   testing::Test::TearDown();
 }
 
 void AuraTestBase::RunAllPendingInMessageLoop() {
   message_loop_.RunAllPendingWithDispatcher(
       RootWindow::GetInstance()->GetDispatcher());
 }
 
 }  // namespace test
 }  // namespace aura