Revert "Revert"Adding a WindowAndroidHelper class"

chrome/browser/ui/android/window_android_helper.cc

+// Copyright (c) 2012 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/ui/android/window_android_helper.h"
+
+#include "content/public/browser/web_contents.h"
+#include "ui/gfx/android/window_android.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(WindowAndroidHelper)
+
+WindowAndroidHelper::WindowAndroidHelper(content::WebContents* web_contents) {
+}
+
+WindowAndroidHelper::~WindowAndroidHelper() {
+}
+
+void WindowAndroidHelper::SetWindowAndroid(ui::WindowAndroid* window_android) {
+  window_android_ = window_android;
+}
+
+ui::WindowAndroid* WindowAndroidHelper::GetWindowAndroid() {
+  return window_android_;
+}