New snippets now replace old snippets and do not merge

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>
 
 #include "base/macros.h"
 #include "components/ntp_snippets/category.h"
 
 namespace ntp_snippets {
 
 // Creates and orders Category instances.
 class CategoryFactory {
  public:
@@ skipping 17 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;
 
+  // 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_