[NTP Snippets] Introduce ContentSuggestion::ID

components/ntp_snippets/category_factory.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_CATEGORY_FACTORY_H_
 #define COMPONENTS_NTP_SNIPPETS_CATEGORY_FACTORY_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 26 matching lines @@
 
   // Compares the given categories according to a strict ordering, returning
   // true if and only if |left| is strictly less than |right|.
   // This method satisfies the "Compare" contract required by sort algorithms.
   // The order is determined as follows: All local categories go first, in a
   // specific order hard-coded in the |CategoryFactory| constructor. All remote
   // categories follow in the order in which they were first created through
   // |FromRemoteCategory|.
   bool CompareCategories(const Category& left, const Category& right) const;
 
-  // TODO(treib): Remove the following 3 functions from here once we move to a
-  // more structured identification than the unique_id string and thus once we
-  // eliminate these functions. See crbug.com/649048.
-
-  // Creates a unique ID. The given |within_category_id| must be unique among
-  // all suggestion IDs from this provider for the given |category|. This method
-  // combines it with the |category| to form an ID that is unique
-  // application-wide, because this provider is the only one that provides
-  // suggestions for that category.
-  std::string MakeUniqueID(Category category,
-                           const std::string& within_category_id) const;
-
-  // Reverse functions for MakeUniqueID()
-  Category GetCategoryFromUniqueID(const std::string& unique_id);
-  std::string GetWithinCategoryIDFromUniqueID(
-      const std::string& unique_id) const;
-
  private:
   bool CategoryExists(int id);
   void AddKnownCategory(KnownCategories known_category);
   Category InternalFromID(int id);
 
   // Stores all known categories in the order which is also returned by
   // |CompareCategories|.
   std::vector<Category> ordered_categories_;
 
   DISALLOW_COPY_AND_ASSIGN(CategoryFactory);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_CATEGORY_FACTORY_H_