Adds an experiment that enabled SuggestionsService suggestions (MostLikely) on LocalNTP

chrome/browser/resources/local_ntp/most_visited_single.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. */
 
  // Single iframe for NTP tiles.
 (function() {
 'use strict';
 
 
 /**
@@ skipping 259 matching lines @@
 /**
  * Called when the host page wants to add a suggestion tile.
  * For Most Visited, it grabs the data from Chrome and pass on.
  * For host page generated it just passes the data.
  * @param {object} args Data for the tile to be rendered.
  */
 var addTile = function(args) {
   if (args.rid) {
     var data = chrome.embeddedSearch.searchBox.getMostVisitedItemData(args.rid);
     data.tid = data.rid;
-    data.thumbnailUrls = [data.thumbnailUrl];
-    data.faviconUrl = 'chrome-search://favicon/size/16@' +
-        window.devicePixelRatio + 'x/' + data.renderViewId + '/' + data.tid;
+    if (data.thumbnailUrl) {
+      data.thumbnailUrls = [data.thumbnailUrl];

[Mathieu, 2015/07/28 13:32:42]

should we make sure data.thumbnailUrls is not undefined when exiting addTile? I
know in your proposed change it wouldn't, but later on that may change.
renderTile wouldn't handle it well.

[fserb, 2015/07/28 17:55:29]

Done.

+    }
+    if (!data.faviconUrl) {
+      data.faviconUrl = 'chrome-search://favicon/size/16@' +
+          window.devicePixelRatio + 'x/' + data.renderViewId + '/' + data.tid;
+    }
     tiles.appendChild(renderTile(data));
     logEvent(LOG_TYPE.NTP_CLIENT_SIDE_SUGGESTION);
   } else if (args.id) {
     tiles.appendChild(renderTile(args));
     logEvent(LOG_TYPE.NTP_SERVER_SIDE_SUGGESTION);
   } else {
     tiles.appendChild(renderTile(null));
   }
 };
 
@@ skipping 313 matching lines @@
     var html = document.querySelector('html');
     html.dir = 'rtl';
   }
 
   window.addEventListener('message', handlePostMessage);
 };
 
 
 window.addEventListener('DOMContentLoaded', init);
 })();