[Favicon] Add new fallback icon rendering flow.

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

Index: chrome/browser/ui/webui/ntp/most_visited_handler.cc
diff --git a/chrome/browser/ui/webui/ntp/most_visited_handler.cc b/chrome/browser/ui/webui/ntp/most_visited_handler.cc
index 16d5b7cf42305d34e8e0e3c94f20a100a7b79600..39a1f2fb5c85c239559cf13fcd4d04a4700fe738 100644
--- a/chrome/browser/ui/webui/ntp/most_visited_handler.cc
+++ b/chrome/browser/ui/webui/ntp/most_visited_handler.cc
@@ -27,6 +27,7 @@
 #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"
@@ -79,6 +80,9 @@ void MostVisitedHandler::RegisterMessages() {
   // 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));