[Favicon] Add new fallback icon rendering flow.

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 31b68d6fd76e44fe86b706559255f50e5f94f57d..d0f4d55f00fafdffccc4f259d24935b511f6a365 100644
--- a/chrome/browser/search/instant_service.cc
+++ b/chrome/browser/search/instant_service.cc
@@ -19,6 +19,7 @@
 #include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/thumbnails/thumbnail_list_source.h"
 #include "chrome/browser/ui/search/instant_search_prerenderer.h"
+#include "chrome/browser/ui/webui/fallback_icon_source.h"
 #include "chrome/browser/ui/webui/favicon_source.h"
 #include "chrome/browser/ui/webui/ntp/thumbnail_source.h"
 #include "chrome/browser/ui/webui/theme_source.h"
@@ -122,6 +123,7 @@ InstantService::InstantService(Profile* profile)
   content::URLDataSource::Add(profile_, new ThumbnailListSource(profile_));
 #endif  // !defined(OS_ANDROID)
 
+  content::URLDataSource::Add(profile_, new FallbackIconSource());
   content::URLDataSource::Add(
       profile_, new FaviconSource(profile_, FaviconSource::FAVICON));
   content::URLDataSource::Add(profile_, new MostVisitedIframeSource());