[NTP::SectionOrder] Propagate new order through ContentSuggestionsService.

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 82 matching lines @@
                             std::unique_ptr<CategoryRanker> category_ranker);
   ~ContentSuggestionsService() override;
 
   // Inherited from KeyedService.
   void Shutdown() override;
 
   static void RegisterProfilePrefs(PrefRegistrySimple* registry);
 
   State state() { return state_; }
 
-  // Gets all categories for which a provider is registered. The categories
-  // may or may not be available, see |GetCategoryStatus()|.
-  const std::vector<Category>& GetCategories() const { return categories_; }
+  // Gets all categories for which a provider is registered. The categories may
+  // or may not be available, see |GetCategoryStatus()|. The order in which the
+  // categories are returned is the order in which they should be displayed.
+  const std::vector<Category>& GetCategories();

[Marc Treib, 2016/12/19 13:22:46]

Hm, it's a bit unfortunate that this can't be const anymore.
Since |categories_| has an undefined order now anyway, maybe just return a
sorted copy?

[vitaliii, 2016/12/19 15:28:59]

Done.

 
   // Gets the status of a category.
   CategoryStatus GetCategoryStatus(Category category) const;
 
   // Gets the meta information of a category.
   base::Optional<CategoryInfo> GetCategoryInfo(Category category) const;
 
   // Gets the available suggestions for a category. The result is empty if the
   // category is available and empty, but also if the category is unavailable
   // for any reason, see |GetCategoryStatus()|.
@@ skipping 161 matching lines @@
   std::map<Category, ContentSuggestionsProvider*, Category::CompareByID>
       providers_by_category_;
 
   // All dismissed categories and their providers. These may be restored by
   // RestoreDismissedCategories(). The provider can be null if the dismissed
   // category has received no updates since initialisation.
   // (see RestoreDismissedCategoriesFromPrefs())
   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_|.
+  // All current suggestion categories in undefined order. 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>
       suggestions_by_category_;
 
   // Observer for the SigninManager. All observers are notified when the signin
@@ skipping 22 matching lines @@
 
   // Provides order for categories.
   std::unique_ptr<CategoryRanker> category_ranker_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentSuggestionsService);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_CONTENT_SUGGESTIONS_SERVICE_H_