Remove base::Value::CreateNullValue

components/sync_preferences/pref_service_syncable_unittest.cc

 // 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.
 
 #include "components/sync_preferences/pref_service_syncable.h"
 
 #include <stdint.h>
 
 #include <memory>
 
@@ skipping 521 matching lines @@
   EXPECT_FALSE(FindValue(kStringPrefName, out).get());
 }
 
 TEST_F(PrefServiceSyncableTest, DeletePreference) {
   prefs_.SetString(kStringPrefName, kExampleUrl0);
   const PrefService::Preference* pref = prefs_.FindPreference(kStringPrefName);
   EXPECT_FALSE(pref->IsDefaultValue());
 
   InitWithNoSyncData();
 
-  std::unique_ptr<base::Value> null_value = base::Value::CreateNullValue();
+  auto null_value = base::MakeUnique<base::Value>();
   syncer::SyncChangeList list;
   list.push_back(MakeRemoteChange(1, kStringPrefName, *null_value,
                                   SyncChange::ACTION_DELETE));
   pref_sync_service_->ProcessSyncChanges(FROM_HERE, list);
   EXPECT_TRUE(pref->IsDefaultValue());
 }
 
 TEST_F(PrefServiceSyncableTest, RegisterMergeDataFinishedCallback) {
   int num_callbacks = 0;
 
   prefs_.RegisterMergeDataFinishedCallback(
       base::Bind(&Increment, &num_callbacks));
   EXPECT_EQ(0, num_callbacks);
 
   InitWithNoSyncData();
   EXPECT_EQ(1, num_callbacks);
 }
 
 }  // namespace
 
 }  // namespace sync_preferences