[Chromoting] Move shared webapp JS files from crd/js -> base/js

remoting/webapp/base/js/clipboard.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview
  * A class for moving clipboard items between the plugin and the OS.
  */
 
 /** @suppress {duplicate} */
@@ skipping 195 matching lines @@
  * @private
  */
 remoting.Clipboard.prototype.onCopy_ = function(event) {
   if (event && event.clipboardData && this.toOs_(event.clipboardData)) {
     // The default action may overwrite items that we added to clipboardData.
     event.preventDefault();
   }
 };
 
 })();