Remove TopSites notification in favor of Observers

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

Index: chrome/browser/ui/webui/ntp/suggestions_page_handler.cc
diff --git a/chrome/browser/ui/webui/ntp/suggestions_page_handler.cc b/chrome/browser/ui/webui/ntp/suggestions_page_handler.cc
index 4d606fe2d0c02ebc3797f0e909e93accedd24cf1..2689c20e21f22b1e44fe47594ab1afa111b51ebc 100644
--- a/chrome/browser/ui/webui/ntp/suggestions_page_handler.cc
+++ b/chrome/browser/ui/webui/ntp/suggestions_page_handler.cc
@@ -15,7 +15,6 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/values.h"
-#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/favicon_source.h"
@@ -28,7 +27,6 @@
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
-#include "content/public/browser/notification_source.h"
 #include "content/public/browser/url_data_source.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
@@ -39,7 +37,8 @@
 using base::UserMetricsAction;
 
 SuggestionsHandler::SuggestionsHandler()
-    : got_first_suggestions_request_(false),
+    : scoped_observer_(this),
+      got_first_suggestions_request_(false),
       suggestions_viewed_(false),
       user_action_logged_(false) {
 }
@@ -76,10 +75,9 @@ void SuggestionsHandler::RegisterMessages() {
     // show the new tab page.
     top_sites->SyncWithHistory();
 
-    // Register for notification when TopSites changes so that we can update
-    // ourself.
-    registrar_.Add(this, chrome::NOTIFICATION_TOP_SITES_CHANGED,
-                   content::Source<history::TopSites>(top_sites));
+    // Register as TopSitesObserver so that we can update ourselves when the
+    // TopSites changes.
+    scoped_observer_.Add(top_sites);
   }
 
   // Setup the suggestions sources.
@@ -175,11 +173,10 @@ void SuggestionsHandler::HandleSuggestedSitesSelected(
   suggestions_viewed_ = true;
 }
 
-void SuggestionsHandler::Observe(int type,
-                                 const content::NotificationSource& source,
-                                 const content::NotificationDetails& details) {
-  DCHECK_EQ(type, chrome::NOTIFICATION_TOP_SITES_CHANGED);
+void SuggestionsHandler::TopSitesLoaded(history::TopSites* top_sites) {
+}
 
+void SuggestionsHandler::TopSitesChanged(history::TopSites* top_sites) {
   // Suggestions urls changed, query again.
   suggestions_combiner_->FetchItems(Profile::FromWebUI(web_ui()));
 }