[Fallback Icons] Refactor FallbackIconService to be a BrowserContext-level singleton

chrome/browser/ui/webui/ntp/most_visited_handler.cc

 // 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 "chrome/browser/ui/webui/ntp/most_visited_handler.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 63 matching lines @@
 void MostVisitedHandler::RegisterMessages() {
   Profile* profile = Profile::FromWebUI(web_ui());
   // Set up our sources for thumbnail and favicon data.
   content::URLDataSource::Add(profile, new ThumbnailSource(profile, false));
   content::URLDataSource::Add(profile, new ThumbnailSource(profile, true));
 
   // Set up our sources for top-sites data.
   content::URLDataSource::Add(profile, new ThumbnailListSource(profile));
 
   // Register chrome://fallback-icon as a data source for fallback icons.
-  content::URLDataSource::Add(profile, new FallbackIconSource());
+  content::URLDataSource::Add(profile, new FallbackIconSource(profile));
 
   // Register chrome://favicon as a data source for favicons.
   content::URLDataSource::Add(
       profile, new FaviconSource(profile, FaviconSource::FAVICON));
 
   scoped_refptr<history::TopSites> top_sites =
       TopSitesFactory::GetForProfile(profile);
   if (top_sites) {
     // TopSites updates itself after a delay. This is especially noticable when
     // your profile is empty. Ask TopSites to update itself when we're about to
@@ skipping 176 matching lines @@
   return base::MD5String(url);
 }
 
 // static
 void MostVisitedHandler::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterDictionaryPref(
       prefs::kNtpMostVisitedURLsBlacklist,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }