[Most Visited] Check for Sync state when using SuggestionsService.

chrome/browser/android/most_visited_sites.h

Index: chrome/browser/android/most_visited_sites.h
diff --git a/chrome/browser/android/most_visited_sites.h b/chrome/browser/android/most_visited_sites.h
index 39eccebdd8d9bfa93ce7dbb8da17523bcfb5a269..378e9041a57e93548000ccf7c0b96e70c5ac18c0 100644
--- a/chrome/browser/android/most_visited_sites.h
+++ b/chrome/browser/android/most_visited_sites.h
@@ -12,6 +12,7 @@
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/sync/profile_sync_service_observer.h"
 #include "components/suggestions/proto/suggestions.pb.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
@@ -21,7 +22,8 @@ class SuggestionsService;
 }
 
 // Provides the list of most visited sites and their thumbnails to Java.
-class MostVisitedSites : public content::NotificationObserver {
+class MostVisitedSites : public ProfileSyncServiceObserver,
+                         public content::NotificationObserver {
  public:
   typedef base::Callback<
       void(base::android::ScopedJavaGlobalRef<jobject>* bitmap,
@@ -47,6 +49,9 @@ class MostVisitedSites : public content::NotificationObserver {
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // ProfileSyncServiceObserver implementation.
+  virtual void OnStateChanged() OVERRIDE;
+
   // Registers JNI methods.
   static bool Register(JNIEnv* env);
 
@@ -98,6 +103,9 @@ class MostVisitedSites : public content::NotificationObserver {
   // The maximum number of most visited sites to return.
   int num_sites_;
 
+  // Whether the sync service is initialized.
+  bool sync_initialized_;
+
   // Whether the user is in a control group for the purposes of logging.
   bool is_control_group_;