Revert of Integrate registry_hash_store_contents with the rest of tracked prefs.

components/user_prefs/tracked/dictionary_hash_store_contents.cc

 // Copyright (c) 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.
 
 #include "components/user_prefs/tracked/dictionary_hash_store_contents.h"
 
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/values.h"
@@ skipping 10 matching lines @@
     : storage_(storage) {
 }
 
 // static
 void DictionaryHashStoreContents::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterDictionaryPref(kPreferenceMACs);
   registry->RegisterStringPref(kSuperMACPref, std::string());
 }
 
-bool DictionaryHashStoreContents::IsCopyable() const {
-  return false;
-}
-
-std::unique_ptr<HashStoreContents> DictionaryHashStoreContents::MakeCopy()
-    const {
-  NOTREACHED() << "DictionaryHashStoreContents does not support MakeCopy";
-  return nullptr;
-}
-
 base::StringPiece DictionaryHashStoreContents::GetUMASuffix() const {
   // To stay consistent with existing reported data, do not append a suffix
   // when reporting UMA stats for this content.
   return base::StringPiece();
 }
 
 void DictionaryHashStoreContents::Reset() {
   storage_->Remove(kPreferenceMACs, NULL);
 }
 
@@ skipping 73 matching lines @@
 
 base::DictionaryValue* DictionaryHashStoreContents::GetMutableContents(
     bool create_if_null) {
   base::DictionaryValue* macs_dict = NULL;
   storage_->GetDictionary(kPreferenceMACs, &macs_dict);
   if (!macs_dict && create_if_null) {
     macs_dict = new base::DictionaryValue;
     storage_->Set(kPreferenceMACs, macs_dict);
   }
   return macs_dict;
-}
+}