Typecheck JS files for chrome://history

ui/webui/resources/js/util.js

 // Copyright (c) 2012 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.
 
 <include src="assert.js">
 
 /**
  * Alias for document.getElementById.
  * @param {string} id The ID of the element to find.
  * @return {HTMLElement} The found element or null if not found.
@@ skipping 150 matching lines @@
 
   var newQuery = '';
   for (var q in query) {
     newQuery += (newQuery ? '&' : '?') + q + '=' + query[q];
   }
 
   return location.origin + location.pathname + newQuery + location.hash;
 }
 
 /**
- * @param {Node} el An element to search for ancestors with |className|.
+ * @param {Element} el An element to search for ancestors with |className|.
  * @param {string} className A class to search for.
- * @return {Node} A node with class of |className| or null if none is found.
+ * @return {Element} A node with class of |className| or null if none is found.
  */
 function findAncestorByClass(el, className) {
-  return findAncestor(el, function(el) {
+  return /** @type {Element} */(findAncestor(el, function(el) {
     return el.classList && el.classList.contains(className);
-  });
+  }));
 }
 
 /**
  * Return the first ancestor for which the {@code predicate} returns true.
  * @param {Node} node The node to check.
  * @param {function(Node):boolean} predicate The function that tests the
  *     nodes.
  * @return {Node} The found ancestor or null if not found.
  */
 function findAncestor(node, predicate) {
@@ skipping 243 matching lines @@
  * @param {number} maxLength The maximum length allowed for the string.
  * @return {string} The original string if its length does not exceed
  *     |maxLength|. Otherwise the first |maxLength| - 1 characters with '...'
  *     appended.
  */
 function elide(original, maxLength) {
   if (original.length <= maxLength)
     return original;
   return original.substring(0, maxLength - 1) + '\u2026';
 }