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

chrome/browser/search/instant_service.cc

Index: chrome/browser/search/instant_service.cc
diff --git a/chrome/browser/search/instant_service.cc b/chrome/browser/search/instant_service.cc
index 818cec90f3e0f7c82cf4aaf6ea1eb70c13c3046a..77b13bc78e929244e53295218341d5e2d2be3c51 100644
--- a/chrome/browser/search/instant_service.cc
+++ b/chrome/browser/search/instant_service.cc
@@ -5,6 +5,8 @@
 #include "chrome/browser/search/instant_service.h"
 
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/favicon/fallback_icon_service_factory.h"
+#include "chrome/browser/favicon/favicon_service_factory.h"
 #include "chrome/browser/history/top_sites_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/instant_io_context.h"
@@ -25,7 +27,10 @@
 #include "chrome/browser/ui/webui/ntp/thumbnail_source.h"
 #include "chrome/browser/ui/webui/theme_source.h"
 #include "chrome/common/render_messages.h"
+#include "components/favicon/core/fallback_icon_service.h"
+#include "components/favicon/core/favicon_service.h"
 #include "components/history/core/browser/top_sites.h"
+#include "components/keyed_service/core/service_access_type.h"
 #include "components/search_engines/template_url_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
@@ -126,8 +131,15 @@ InstantService::InstantService(Profile* profile)
   content::URLDataSource::Add(profile_, new ThumbnailListSource(profile_));
 #endif  // !defined(OS_ANDROID)
 
-  content::URLDataSource::Add(profile_, new LargeIconSource(profile));
-  content::URLDataSource::Add(profile_, new FallbackIconSource());
+  FaviconService* favicon_service = FaviconServiceFactory::GetForProfile(
+      profile_, ServiceAccessType::EXPLICIT_ACCESS);
+  FallbackIconService* fallback_icon_service =
+      FallbackIconServiceFactory::GetForBrowserContext(profile_);
+
+  content::URLDataSource::Add(profile_,
+      new LargeIconSource(favicon_service, fallback_icon_service));
+  content::URLDataSource::Add(
+      profile_, new FallbackIconSource(fallback_icon_service));
   content::URLDataSource::Add(
       profile_, new FaviconSource(profile_, FaviconSource::FAVICON));
   content::URLDataSource::Add(profile_, new MostVisitedIframeSource());