[headless] AddWindowTreeClient

headless/lib/browser/headless_window_tree_client.cc

Index: headless/lib/browser/headless_window_tree_client.cc
diff --git a/headless/lib/browser/headless_window_tree_client.cc b/headless/lib/browser/headless_window_tree_client.cc
new file mode 100644
index 0000000000000000000000000000000000000000..be797ce3032c3cb4ca4d9e1bcd311471b6fdde94
--- /dev/null
+++ b/headless/lib/browser/headless_window_tree_client.cc
@@ -0,0 +1,27 @@
+// Copyright (c) 2016 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 "headless/lib/browser/headless_window_tree_client.h"
+
+#include "ui/aura/window.h"
+
+namespace headless {
+
+HeadlessWindowTreeClient::HeadlessWindowTreeClient(aura::Window* root_window)
+    : root_window_(root_window) {
+  aura::client::SetWindowTreeClient(root_window_, this);
+}
+
+HeadlessWindowTreeClient::~HeadlessWindowTreeClient() {
+  aura::client::SetWindowTreeClient(root_window_, nullptr);
+}
+
+aura::Window* HeadlessWindowTreeClient::GetDefaultParent(
+    aura::Window* context,
+    aura::Window* window,
+    const gfx::Rect& bounds) {
+  return root_window_;
+}
+
+}  // namespace headless