[MD History] Add full time hover text to dates in history items.

chrome/browser/resources/md_history/history_item.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.
 
 /**
  * @param {!Element} root
  * @param {?Element} boundary
  * @param {cr.ui.FocusRow.Delegate} delegate
  * @constructor
  * @extends {cr.ui.FocusRow}
@@ skipping 282 matching lines @@
      * @param {string} historyDate Date of the current result.
      * @param {string} search The search term associated with these results.
      * @return {string} The title for this history card.
      * @private
      */
     cardTitle_: function(numberOfItems, historyDate, search) {
       if (!search)
         return this.item.dateRelativeDay;
       return HistoryItem.searchResultsTitle(numberOfItems, search);
     },
+
+    /**
+     * @private
+     */

[Dan Beam, 2016/10/28 20:43:28]

nit: /** @private */

+    addTimeTitle_: function() {
+      var el = this.$['time-accessed'];
+      el.setAttribute('title', new Date(this.item.time).toString());
+      this.unlisten(el, 'mouseover', 'addTimeTitle_');
+    },
   });
 
   /**
    * Check whether the time difference between the given history item and the
    * next one is large enough for a spacer to be required.
    * @param {Array<HistoryEntry>} visits
    * @param {number} currentIndex
    * @param {string} searchedTerm
    * @return {boolean} Whether or not time gap separator is required.
    */
@@ skipping 17 matching lines @@
    * @return {string} The title for a page of search results.
    */
   HistoryItem.searchResultsTitle = function(numberOfResults, searchTerm) {
     var resultId = numberOfResults == 1 ? 'searchResult' : 'searchResults';
     return loadTimeData.getStringF('foundSearchResults', numberOfResults,
         loadTimeData.getString(resultId), searchTerm);
   };
 
   return { HistoryItem: HistoryItem };
 });