[Sync] Ensure referrer is recorded regardless of policy conversion

components/sessions/content/content_serialized_navigation_driver.h

 // Copyright 2014 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_SESSIONS_CONTENT_CONTENT_SERIALIZED_NAVIGATION_DRIVER_H_
 #define COMPONENTS_SESSIONS_CONTENT_CONTENT_SERIALIZED_NAVIGATION_DRIVER_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 18 matching lines @@
 
   // Returns the singleton ContentSerializedNavigationDriver.  Almost all
   // callers should use SerializedNavigationDriver::Get() instead.
   static ContentSerializedNavigationDriver* GetInstance();
 
   // Allows an embedder to override the instance returned by GetInstance().
   static void SetInstance(ContentSerializedNavigationDriver* instance);
 
   // SerializedNavigationDriver implementation.
   int GetDefaultReferrerPolicy() const override;
-  bool MapReferrerPolicyToOldValues(int referrer_policy,
-                                    int* mapped_referrer_policy) const override;
-  bool MapReferrerPolicyToNewValues(int referrer_policy,
-                                    int* mapped_referrer_policy) const override;
   std::string GetSanitizedPageStateForPickle(
       const SerializedNavigationEntry* navigation) const override;
   void Sanitize(SerializedNavigationEntry* navigation) const override;
   std::string StripReferrerFromPageState(
       const std::string& page_state) const override;
 
   // Registers a handler that is used to read and write the extended
   // info stored in SerializedNavigationEntry. As part of serialization |key|
   // is written to disk, as such once a handler is registered it should always
   // be registered to the same key.
@@ skipping 15 matching lines @@
   friend class ContentSerializedNavigationBuilderTest;
 
   ExtendedInfoHandlerMap extended_info_handler_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentSerializedNavigationDriver);
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_CONTENT_CONTENT_SERIALIZED_NAVIGATION_DRIVER_H_