[NTP Snippets] Schedule periodic fetching

components/ntp_snippets/ntp_snippets_service.h

 // Copyright 2015 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_NTP_SNIPPETS_SERVICE_H_
 #define COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/sequenced_task_runner.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/ntp_snippets/inner_iterator.h"
 #include "components/ntp_snippets/ntp_snippet.h"
 #include "components/ntp_snippets/ntp_snippets_fetcher.h"
+#include "components/ntp_snippets/ntp_snippets_scheduler.h"
 
 namespace ntp_snippets {
 
 class NTPSnippetsServiceObserver;
 
 // Stores and vend fresh content data for the NTP.
 class NTPSnippetsService : public KeyedService, NTPSnippetsFetcher::Observer {
  public:
   using NTPSnippetStorage = std::vector<scoped_ptr<NTPSnippet>>;
   using const_iterator =
       InnerIterator<NTPSnippetStorage::const_iterator, const NTPSnippet>;
 
   // |application_language_code| should be a ISO 639-1 compliant string. Aka
   // 'en' or 'en-US'. Note that this code should only specify the language, not
   // the locale, so 'en_US' (english language with US locale) and 'en-GB_US'
   // (British english person in the US) are not language code.
   NTPSnippetsService(scoped_refptr<base::SequencedTaskRunner> file_task_runner,
                      const std::string& application_language_code,
+                     NTPSnippetsScheduler* scheduler,
                      scoped_ptr<NTPSnippetsFetcher> snippets_fetcher);
   ~NTPSnippetsService() override;
 
+  void Init(bool enabled);
+
   // Fetches snippets from the server. |overwrite| is true if existing snippets
   // should be overwritten.
   void FetchSnippets(bool overwrite);
 
   // Inherited from KeyedService.
   void Shutdown() override;
 
   // True once the data is loaded in memory and available to loop over.
   bool is_loaded() { return loaded_; }
 
@@ skipping 40 matching lines @@
 
   // All the suggestions.
   NTPSnippetStorage snippets_;
 
   // The ISO 639-1 code of the language used by the application.
   const std::string application_language_code_;
 
   // The observers.
   base::ObserverList<NTPSnippetsServiceObserver> observers_;
 
+  // Scheduler for fetching snippets. Not owned.
+  NTPSnippetsScheduler* scheduler_;
+
   // The snippets fetcher
   scoped_ptr<NTPSnippetsFetcher> snippets_fetcher_;
 
   // The callback from the snippets fetcher
   scoped_ptr<NTPSnippetsFetcher::SnippetsAvailableCallbackList::Subscription>
       snippets_fetcher_callback_;
 
   base::WeakPtrFactory<NTPSnippetsService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsService);
 };
 
 class NTPSnippetsServiceObserver {
  public:
   // Send everytime the service loads a new set of data.
   virtual void NTPSnippetsServiceLoaded(NTPSnippetsService* service) = 0;
   // Send when the service is shutting down.
   virtual void NTPSnippetsServiceShutdown(NTPSnippetsService* service) = 0;
 
  protected:
   virtual ~NTPSnippetsServiceObserver() {}
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_