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

chrome/browser/search/instant_service.cc

 // Copyright 2013 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/search/instant_service.h"
 
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/history/top_sites_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/instant_io_context.h"
@@ skipping 107 matching lines @@
 
   // TODO(aurimas) remove this #if once instant_service.cc is no longer compiled
   // on Android.
 #if !defined(OS_ANDROID)
   content::URLDataSource::Add(profile_, new LocalNtpSource(profile_));
   content::URLDataSource::Add(profile_, new ThumbnailSource(profile_, false));
   content::URLDataSource::Add(profile_, new ThumbnailSource(profile_, true));
   content::URLDataSource::Add(profile_, new ThumbnailListSource(profile_));
 #endif  // !defined(OS_ANDROID)
 
-  content::URLDataSource::Add(profile_, new FallbackIconSource());
+  content::URLDataSource::Add(profile_, new FallbackIconSource(profile_));
   content::URLDataSource::Add(
       profile_, new FaviconSource(profile_, FaviconSource::FAVICON));
   content::URLDataSource::Add(profile_, new MostVisitedIframeSource());
   content::URLDataSource::Add(
       profile_, new suggestions::SuggestionsSource(profile_));
 }
 
 InstantService::~InstantService() {
   if (template_url_service_)
     template_url_service_->RemoveObserver(this);
@@ skipping 298 matching lines @@
 }
 
 void InstantService::ResetInstantSearchPrerenderer() {
   if (!chrome::ShouldPrefetchSearchResults())
     return;
 
   GURL url(chrome::GetSearchResultPrefetchBaseURL(profile_));
   instant_prerenderer_.reset(
       url.is_valid() ? new InstantSearchPrerenderer(profile_, url) : NULL);
 }