Fix NTP not to slide with mouse

chrome/browser/resources/ntp4/tools/externs.js

-// Copyright (c) 2011 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.
-
-// externs.js contains variable declarations for the closure compiler
-// This isn't actually used when running the code.
-
-// JSCompiler doesn't know about this new Element property
-Element.prototype.classList = {};
-/** @param {string} c */
-Element.prototype.classList.remove = function(c) {};
-/** @param {string} c */
-Element.prototype.classList.add = function(c) {};
-/** @param {string} c */
-Element.prototype.classList.contains = function(c) {};
-
-/**
- *  @constructor
- *  @extends {Event}
- */
-var CustomEvent = function() {};
-CustomEvent.prototype.initCustomEvent =
-  function(eventType, bubbles, cancellable, detail) {};
-/** @type {TouchHandler.EventDetail} */
-CustomEvent.prototype.detail;
-
-
-/** @param {string} s
- *  @return {string}
- */
-var url = function(s) {};
-
-/**
- * @param {string} type
- * @param {EventListener|function(Event):(boolean|undefined)} listener
- * @param {boolean=} opt_useCapture
- * @return {undefined}
- * @suppress {checkTypes}
- */
-Window.prototype.addEventListener = function(type, listener, opt_useCapture) {};