Clean up old legacy preference migration logic.

components/user_prefs/tracked/hash_store_contents.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_USER_PREFS_TRACKED_HASH_STORE_CONTENTS_H_
 #define COMPONENTS_USER_PREFS_TRACKED_HASH_STORE_CONTENTS_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 18 matching lines @@
   class MutableDictionary {
    public:
     virtual ~MutableDictionary() {}
     // Returns the DictionaryValue, which will be created if it does not already
     // exist.
     virtual base::DictionaryValue* operator->() = 0;
   };
 
   virtual ~HashStoreContents() {}
 
-  // Returns the hash-store ID. May be empty.
-  virtual std::string hash_store_id() const = 0;
-
   // Discards all data related to this hash store.
   virtual void Reset() = 0;
 
   // Indicates whether any data is currently stored for this hash store.
   virtual bool IsInitialized() const = 0;
 
   // Retrieves the contents of this hash store. May return NULL if the hash
   // store has not been initialized.
   virtual const base::DictionaryValue* GetContents() const = 0;
 
   // Provides mutable access to the contents of this hash store.
   virtual std::unique_ptr<MutableDictionary> GetMutableContents() = 0;
 
   // Retrieves the super MAC value previously stored by SetSuperMac. May be
   // empty if no super MAC has been stored.
   virtual std::string GetSuperMac() const = 0;
 
   // Stores a super MAC value for this hash store.
   virtual void SetSuperMac(const std::string& super_mac) = 0;
 };
 
 #endif  // COMPONENTS_USER_PREFS_TRACKED_HASH_STORE_CONTENTS_H_