Rename StackingClient -> WindowTreeClient

ui/aura/test/test_window_tree_client.cc

+// Copyright (c) 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 "ui/aura/test/test_window_tree_client.h"
+
+#include "ui/aura/window.h"
+
+namespace aura {
+namespace test {
+
+TestWindowTreeClient::TestWindowTreeClient(Window* root_window)
+    : root_window_(root_window) {
+  client::SetWindowTreeClient(root_window_, this);
+}
+
+TestWindowTreeClient::~TestWindowTreeClient() {
+  client::SetWindowTreeClient(root_window_, NULL);
+}
+
+Window* TestWindowTreeClient::GetDefaultParent(Window* context,
+                                               Window* window,
+                                               const gfx::Rect& bounds) {
+  return root_window_;
+}
+
+}  // namespace test
+}  // namespace aura