Defer effects of HandleViewed/HandleClosed until prefs are loaded again.

ios/chrome/browser/notification_promo.h

 // Copyright (c) 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IOS_CHROME_BROWSER_NOTIFICATION_PROMO_H_
 #define IOS_CHROME_BROWSER_NOTIFICATION_PROMO_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 39 matching lines @@
   // Can this promo be shown?
   bool CanShow() const;
 
   // The time when this promo can start being viewed.
   double StartTime() const;
   // The time after which this promo no longer can be viewed.
   double EndTime() const;
 
   // Mark the promo as closed when the user dismisses it.
   void HandleClosed();
-  // Mark the promo has having been viewed. This returns true if views
-  // exceeds the maximum allowed.
-  bool HandleViewed();
+  // Mark the promo has having been viewed.
+  void HandleViewed();
 
   const std::string& promo_text() const { return promo_text_; }
   PromoType promo_type() const { return promo_type_; }
   const base::DictionaryValue* promo_payload() const {
     return promo_payload_.get();
   }
 
   // Register preferences.
   static void RegisterPrefs(PrefRegistrySimple* registry);
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
@@ skipping 50 matching lines @@
 
   int views_;
   bool closed_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationPromo);
 };
 
 }  // namespace ios
 
 #endif  // IOS_CHROME_BROWSER_NOTIFICATION_PROMO_H_