Move dart:chrome to dart:_chrome.

tools/dom/src/chrome/chrome.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-part of chrome;
-
-// chrome.app
-class API_ChromeApp {
-  /*
-   * JS Variable
-   */
-  final Object _jsObject;
-
-  /*
-   * Members
-   */
-  API_app_window window;
-  API_app_runtime runtime;
-
-  /*
-   * Constructor
-   */
-  API_ChromeApp(this._jsObject) {
-    var window_object = JS('', '#.window', this._jsObject);
-    if (window_object == null)
-      throw new UnsupportedError('Not supported by current browser.');
-    window = new API_app_window(window_object);
-
-    var runtime_object = JS('', '#.runtime', this._jsObject);
-    if (runtime_object == null)
-      throw new UnsupportedError('Not supported by current browser.');
-    runtime = new API_app_runtime(runtime_object);
-  }
-}
-
-// chrome
-class API_Chrome {
-  /*
-   * JS Variable
-   */
-  Object _jsObject;
-
-  /*
-   * Members
-   */
-  API_ChromeApp app;
-  API_file_system fileSystem;
-
-  /*
-   * Constructor
-   */
-  API_Chrome() {
-    this._jsObject = JS("Object", "chrome");
-    if (this._jsObject == null)
-      throw new UnsupportedError('Not supported by current browser.');
-
-    var app_object = JS('', '#.app', this._jsObject);
-    if (app_object == null)
-      throw new UnsupportedError('Not supported by current browser.');
-    app = new API_ChromeApp(app_object);
-
-    var file_system_object = JS('', '#.fileSystem', this._jsObject);
-    if (file_system_object == null)
-      throw new UnsupportedError('Not supported by current browser.');
-    fileSystem = new API_file_system(file_system_object);
-  }
-}
-
-// The final chrome objects
-final API_Chrome chrome = new API_Chrome();