NTP: Fix metrics recording race condition

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/FakeMostVisitedSites.java

 // 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.
 
 package org.chromium.chrome.browser.ntp;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.chrome.browser.profiles.MostVisitedSites;
 import org.chromium.chrome.browser.profiles.Profile;
 
@@ skipping 55 matching lines @@
     public boolean isUrlBlacklisted(String url) {
         return mBlacklistedUrls.contains(url);
     }
 
     @Override
     public void recordTileTypeMetrics(int[] tileTypes, int[] sources) {
         // Metrics are stubbed out.
     }
 
     @Override
-    public void recordOpenedMostVisitedItem(int index, int tileType) {
+    public void recordOpenedMostVisitedItem(int index, int tileType, int source) {
         //  Metrics are stubbed out.
     }
 }