ntp: add tooltips for all tile types

chrome/browser/resources/ntp4/most_visited_page.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.
 
 cr.define('ntp4', function() {
   'use strict';
 
   var TilePage = ntp4.TilePage;
 
   /**
@@ skipping 46 matching lines @@
               '<div class="thumbnail-shield fills-parent"></div>' +
             '</span>' +
             '<span class="favicon"></span>' +
           '</span>' +
           '<div class="color-stripe"></div>' +
           '<span class="title"></span>';
 
       this.removeAttribute('tabIndex');
       this.data_ = null;
       this.removeAttribute('id');
+      this.title = '';
     },
 
     /**
      * Update the appearance of this tile according to |data|.
      * @param {Object} data A dictionary of relevant data for the page.
      */
     updateForData: function(data) {
       if (this.classList.contains('blacklisted') && data) {
         // Animate appearance of new tile.
         this.classList.add('new-tile-contents');
@@ skipping 19 matching lines @@
       faviconDiv.dir = data.direction;
       if (data.faviconDominantColor)
         this.stripeColor = data.faviconDominantColor;
       else
         chrome.send('getFaviconDominantColor', [faviconUrl, this.id]);
 
       var title = this.querySelector('.title');
       title.textContent = data.title;
       title.dir = data.direction;
 
+      // Sets the tooltip.
+      this.title = data.title;
+
       var thumbnailUrl = data.thumbnailUrl || 'chrome://thumb/' + data.url;
       this.querySelector('.thumbnail').style.backgroundImage =
           url(thumbnailUrl);
 
       this.href = data.url;
 
       this.classList.remove('filler');
     },
 
     /**
@@ skipping 294 matching lines @@
     }
 
     return oldData;
   };
 
   return {
     MostVisitedPage: MostVisitedPage,
     refreshData: refreshData,
   };
 });