Move dart:chrome to dart:_chrome.

tools/dom/src/chrome/custom_dart/app_window.AppWindow.getBounds.dart

Index: tools/dom/src/chrome/custom_dart/app_window.AppWindow.getBounds.dart
===================================================================
--- tools/dom/src/chrome/custom_dart/app_window.AppWindow.getBounds.dart	(revision 27851)
+++ tools/dom/src/chrome/custom_dart/app_window.AppWindow.getBounds.dart	(working copy)
@@ -1,8 +0,0 @@
-// Copyright (c) 2013, 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.
-
-// TODO(sashab, kalman): Fix IDL parser to read function return values
-// correctly. Currently, it just reads void for all functions.
-AppWindowBounds getBounds() =>
-    new AppWindowBounds._proxy(JS('void', '#.getBounds()', this._jsObject));