[NTP::Push] Add Content Suggestions GCM App Handler

components/ntp_snippets/breaking_news/subscription_manager.h

 // Copyright 2017 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 COMPONENTS_NTP_SNIPPETS_BREAKING_NEWS_SUBSCRIPTION_MANAGER_H_
 #define COMPONENTS_NTP_SNIPPETS_BREAKING_NEWS_SUBSCRIPTION_MANAGER_H_
 
 #include "components/ntp_snippets/breaking_news/subscription_json_request.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "url/gurl.h"
 
 class PrefRegistrySimple;
 
 namespace ntp_snippets {
 
+// Class that wraps around the functionality of SubscriptionJsonRequest. It uses
+// the SubscriptionJsonRequest to send subscription and unsubscription requests
+// to the content suggestions server and does the bookkeeping for the data used
+// for subscription. Bookkeeping is required to detect any change (e.g. the
+// token render invalid), and resubscribe accordingly.
 class SubscriptionManager {
  public:
   SubscriptionManager(
       scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
       PrefService* pref_service,
-      const GURL& subscribe_url);
+      const GURL& subscribe_url,
+      const GURL& unsubscribe_url);
 
   ~SubscriptionManager();
 
   void Subscribe(const std::string& token);
+  bool CanSubscribeNow();
   void Unsubscribe(const std::string& token);
+  bool CanUnsubscribeNow();
+  bool IsSubscribed();
 
   static void RegisterProfilePrefs(PrefRegistrySimple* registry);
 
  private:
   std::string subscription_token_;
+  std::string unsubscription_token_;
 
   // Holds the URL request context.
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
 
   std::unique_ptr<internal::SubscriptionJsonRequest> subscription_request_;
+  std::unique_ptr<internal::SubscriptionJsonRequest> unsubscription_request_;
 
   PrefService* pref_service_;
 
-  // API endpoint for subscribing.
+  // API endpoint for subscribing and unsubscribing.
   const GURL subscribe_url_;
+  const GURL unsubscribe_url_;
 
   void DidSubscribe(const ntp_snippets::Status& status);
+  void DidUnsubscribe(const ntp_snippets::Status& status);
 
   DISALLOW_COPY_AND_ASSIGN(SubscriptionManager);
 };
 }
 #endif  // COMPONENTS_NTP_SNIPPETS_BREAKING_NEWS_SUBSCRIPTION_MANAGER_H_