[Favicon] Add new fallback icon rendering flow.

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"
 #include "base/command_line.h"
 #include "base/md5.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/values.h"
 #include "chrome/browser/history/top_sites_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/thumbnails/thumbnail_list_source.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/tabs/tab_strip_model_utils.h"
+#include "chrome/browser/ui/webui/fallback_icon_source.h"
 #include "chrome/browser/ui/webui/favicon_source.h"
 #include "chrome/browser/ui/webui/ntp/new_tab_ui.h"
 #include "chrome/browser/ui/webui/ntp/ntp_stats.h"
 #include "chrome/browser/ui/webui/ntp/thumbnail_source.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "components/history/core/browser/page_usage_data.h"
 #include "components/history/core/browser/top_sites.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "content/public/browser/navigation_controller.h"
@@ skipping 32 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());
+
   // 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
     // show the new tab page.
@@ skipping 175 matching lines @@
   return base::MD5String(url);
 }
 
 // static
 void MostVisitedHandler::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterDictionaryPref(
       prefs::kNtpMostVisitedURLsBlacklist,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }