Combine all suggestions factories into ContentSuggestionsServiceFactory

components/ntp_snippets/content_suggestions_service.h

 // Copyright 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 COMPONENTS_NTP_SNIPPETS_CONTENT_SUGGESTIONS_SERVICE_H_
 #define COMPONENTS_NTP_SNIPPETS_CONTENT_SUGGESTIONS_SERVICE_H_
 
 #include <map>
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/observer_list.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/ntp_snippets/category_factory.h"
 #include "components/ntp_snippets/category_status.h"
 #include "components/ntp_snippets/content_suggestions_provider.h"
 
 namespace gfx {
 class Image;
 }
 
 namespace ntp_snippets {
 
+class NTPSnippetsService;
+
 // Retrieves suggestions from a number of ContentSuggestionsProviders and serves
 // them grouped into categories. There can be at most one provider per category.
 class ContentSuggestionsService : public KeyedService,
                                   public ContentSuggestionsProvider::Observer {
  public:
   using ImageFetchedCallback =
       base::Callback<void(const std::string& suggestion_id, const gfx::Image&)>;
 
   class Observer {
    public:
@@ skipping 56 matching lines @@
   // This will not trigger an update through the observers.
   void DismissSuggestion(const std::string& suggestion_id);
 
   // Observer accessors.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // Registers a new ContentSuggestionsProvider. It must be ensured that at most
   // one provider is registered for every category and that this method is
   // called only once per provider.
-  void RegisterProvider(ContentSuggestionsProvider* provider);
+  void RegisterProvider(std::unique_ptr<ContentSuggestionsProvider> provider);
 
   // Only for debugging use through the internals page.
   // Removes all suggestions from all caches or internal stores in all
   // providers. It does, however, not remove any suggestions from the provider's
   // sources, so if their configuration hasn't changed, they should return the
   // same results when they fetch the next time. In particular, calling this
   // method will not mark any suggestions as dismissed.
   void ClearCachedSuggestionsForDebugging();
 
   // Only for debugging use through the internals page. Some providers
   // internally store a list of dismissed suggestions to prevent them from
   // reappearing. This function clears all such lists in all providers, making
   // dismissed suggestions reappear (only for certain providers).
   void ClearDismissedSuggestionsForDebugging();
 
   CategoryFactory* category_factory() { return &category_factory_; }
 
+  // The reference to the NTPSnippetsService provider should only be set by the
+  // factory and only be used for scheduling, periodic fetching and debugging.
+  NTPSnippetsService* ntp_snippets_service() { return ntp_snippets_service_; }
+  void set_ntp_snippets_service(NTPSnippetsService* ntp_snippets_service) {
+    ntp_snippets_service_ = ntp_snippets_service;
+  }
+
  private:
   friend class ContentSuggestionsServiceTest;
 
   // This is just an arbitrary ordering by ID, used by the maps in this class,
   // because the ordering needs to be constant for maps.
   struct CompareCategoriesByID {
     bool operator()(const Category& left, const Category& right) const;
   };
 
   // Implementation of ContentSuggestionsProvider::Observer.
   void OnNewSuggestions(ContentSuggestionsProvider* provider,
                         Category category,
                         std::vector<ContentSuggestion> suggestions) override;
   void OnCategoryStatusChanged(ContentSuggestionsProvider* provider,
                                Category category,
                                CategoryStatus new_status) override;
-  void OnProviderShutdown(ContentSuggestionsProvider* provider) override;
 
   // Registers the given |provider| for the given |category|, unless it is
   // already registered. Returns true if the category was newly registered or
   // false if it was present before.
   bool RegisterCategoryIfRequired(ContentSuggestionsProvider* provider,
                                   Category category);
 
   // Fires the OnCategoryStatusChanged event for the given |category|.
   void NotifyCategoryStatusChanged(Category category);
 
   // Whether the content suggestions feature is enabled.
   State state_;
 
   // Provides new and existing categories and an order for them.
   CategoryFactory category_factory_;
 
-  // All registered providers. A provider may be contained multiple times, if it
-  // provides multiple categories. The keys of this map are exactly the entries
-  // of |categories_|.
+  // All registered providers, owned by the service.
+  std::vector<std::unique_ptr<ContentSuggestionsProvider>> providers_;
+
+  // All registered categories and their providers. A provider may be contained
+  // multiple times, if it provides multiple categories. The keys of this map
+  // are exactly the entries of |categories_| and the values are a subset of
+  // |providers_|.
   std::map<Category, ContentSuggestionsProvider*, CompareCategoriesByID>
       providers_by_category_;
 
   // All current suggestion categories, in an order determined by the
   // |category_factory_|. This vector contains exactly the same categories as
-  // |providers_|.
+  // |providers_by_category_|.
   std::vector<Category> categories_;
 
   // All current suggestions grouped by category. This contains an entry for
   // every category in |categories_| whose status is an available status. It may
   // contain an empty vector if the category is available but empty (or still
   // loading).
   std::map<Category, std::vector<ContentSuggestion>, CompareCategoriesByID>
       suggestions_by_category_;
 
   // Map used to determine the category of a suggestion (of which only the ID
   // is available). This also determines the provider that delivered the
   // suggestion.
   std::map<std::string, Category> id_category_map_;
 
   base::ObserverList<Observer> observers_;
 
   const std::vector<ContentSuggestion> no_suggestions_;
 
+  // Keep a direct reference to this special provider to redirect scheduling,
+  // background fetching and debugging calls to it. If the NTPSnippetsService is
+  // loaded, it is also present in |providers_|, otherwise this is a nullptr.
+  NTPSnippetsService* ntp_snippets_service_;
+
   DISALLOW_COPY_AND_ASSIGN(ContentSuggestionsService);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_CONTENT_SUGGESTIONS_SERVICE_H_