[NTP Snippets] NTPSnippet cleanup: Make ctor take all IDs at once

components/ntp_snippets/remote/ntp_snippet.h

 // Copyright 2015 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_REMOTE_NTP_SNIPPET_H_
 #define COMPONENTS_NTP_SNIPPETS_REMOTE_NTP_SNIPPET_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 12 matching lines @@
 // Exposed for tests.
 extern const int kArticlesRemoteId;
 extern const int kChromeReaderDefaultExpiryTimeMins;
 
 class SnippetProto;
 
 class NTPSnippet {
  public:
   using PtrVector = std::vector<std::unique_ptr<NTPSnippet>>;
 
-  // Public only so that MakeUnique will work. Don't use directly, call one of
-  // the CreateFrom* methods below instead.
-  // TODO(treib): Make the constructor take the vector of IDs and remove AddIDs.
-  NTPSnippet(const std::string& id, int remote_category_id);
   ~NTPSnippet();
 
   // Creates an NTPSnippet from a dictionary, as returned by Chrome Reader.
   // Returns a null pointer if the dictionary doesn't correspond to a valid
   // snippet. The keys in the dictionary are expected to be the same as the
   // property name, with exceptions documented in the property comment.
   static std::unique_ptr<NTPSnippet> CreateFromChromeReaderDictionary(
       const base::DictionaryValue& dict);
 
   // Creates an NTPSnippet from a dictionary, as returned by Chrome Content
@@ skipping 67 matching lines @@
 
   // The ID of the remote category this snippet belongs to, for use with
   // CategoryFactory::FromRemoteCategory.
   int remote_category_id() const { return remote_category_id_; }
 
   // Public for testing.
   static base::Time TimeFromJsonString(const std::string& timestamp_str);
   static std::string TimeToJsonString(const base::Time& time);
 
  private:
-  void AddIDs(const std::vector<std::string>& ids);
+  NTPSnippet(const std::vector<std::string>& ids, int remote_category_id);
+
+  // base::MakeUnique doesn't work if the ctor is private.
+  static std::unique_ptr<NTPSnippet> MakeUnique(
+      const std::vector<std::string>& ids, int remote_category_id);
 
   // The first ID in the vector is the primary id.
   std::vector<std::string> ids_;
   std::string title_;
   GURL url_;
   std::string publisher_name_;
   GURL amp_url_;
   GURL salient_image_url_;
   std::string snippet_;
   base::Time publish_date_;
   base::Time expiry_date_;
   float score_;
   bool is_dismissed_;
   int remote_category_id_;
 
   DISALLOW_COPY_AND_ASSIGN(NTPSnippet);
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_REMOTE_NTP_SNIPPET_H_