Ntp: show AllDismissedItem when all sections have been dismissed.

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 <set>
@@ skipping 107 matching lines @@
                             const ImageFetchedCallback& callback);
 
   // Dismisses the suggestion with the given |suggestion_id|, if it exists.
   // This will not trigger an update through the observers.
   void DismissSuggestion(const ContentSuggestion::ID& suggestion_id);
 
   // Dismisses the given |category|, if it exists.
   // This will not trigger an update through the observers.
   void DismissCategory(Category category);
 
+  // Restores all dismissed categories.
+  // This will not trigger an update through the observers.
+  void RestoreDismissedCategories();
+
   // 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(std::unique_ptr<ContentSuggestionsProvider> provider);
 
   // Removes history from the specified time range where the URL matches the
@@ skipping 92 matching lines @@
   // 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*, Category::CompareByID>
       providers_by_category_;
 
+  // All dismissed categories and their providers. These may be restored by
+  // RestoreDismissedCategories().
+  std::map<Category, ContentSuggestionsProvider*, Category::CompareByID>
+      dismissed_providers_by_category_;
+
   // All current suggestion categories, in an order determined by the
   // |category_factory_|. This vector contains exactly the same categories as
   // |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>, Category::CompareByID>
@@ skipping 14 matching lines @@
   NTPSnippetsService* ntp_snippets_service_;
 
   UserClassifier user_classifier_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentSuggestionsService);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_CONTENT_SUGGESTIONS_SERVICE_H_