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

ui/aura/test/test_stacking_client.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/test_stacking_client.h"
-
-#include "ui/aura/root_window.h"
-
-namespace aura {
-namespace test {
-
-TestStackingClient::TestStackingClient()
-    : default_container_(new Window(NULL)) {
-  RootWindow::GetInstance()->SetStackingClient(this);
-  default_container_->Init(ui::Layer::LAYER_HAS_NO_TEXTURE);
-  default_container_->SetBounds(
-      gfx::Rect(gfx::Point(), RootWindow::GetInstance()->GetHostSize()));
-  RootWindow::GetInstance()->AddChild(default_container_.get());
-  default_container_->Show();
-}
-
-TestStackingClient::~TestStackingClient() {
-}
-
-void TestStackingClient::AddChildToDefaultParent(Window* window) {
-  default_container_->AddChild(window);
-}
-
-}  // namespace test
-}  // namespace aura