WebUI: Fix middle click link issue in click handler

chrome/browser/resources/shared/js/util.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.
 
 /**
  * The global object.
  * @type {!Object}
  */
 const global = this;
 
@@ skipping 90 matching lines @@
   var afterA = a.nextSibling;
   if (afterA == b) {
     swapDomNodes(b, a);
     return;
   }
   var aParent = a.parentNode;
   b.parentNode.replaceChild(a, b);
   aParent.insertBefore(b, afterA);
 }
 
-/*
- * Handles a click or mouseup on a link. If the link points to a chrome: or
- * file: url, then call into the browser to do the navigation.
- * @return {Object} e The click or mouseup event.
- */
-function handleLinkClickOrMouseUp(e) {
+// Handle click on a link. If the link points to a chrome: or file: url, then
+// call into the browser to do the navigation.
+document.addEventListener('click', function(e) {
   // Allow preventDefault to work.
   if (!e.returnValue)
     return;
 
   var el = e.target;
   if (el.nodeType == Node.ELEMENT_NODE &&
       el.webkitMatchesSelector('A, A *')) {
     while (el.tagName != 'A') {
       el = el.parentElement;
     }
 
     if ((el.protocol == 'file:' || el.protocol == 'about:') &&
-        ((e.button == 0 && e.type == 'click') ||
-        (e.button == 1 && e.type == 'mouseup'))) {
+        (e.button == 0 || e.button == 1)) {
       chrome.send('navigateToUrl',
           [el.href, e.button, e.altKey, e.ctrlKey, e.metaKey, e.shiftKey]);
       e.preventDefault();
     }
   }
-}
-
-document.addEventListener('click', handleLinkClickOrMouseUp);
-document.addEventListener('mouseup', handleLinkClickOrMouseUp);
+});