Remove base::Value::CreateNullValue

chrome/browser/ui/webui/chromeos/first_run/first_run_handler.cc

 // Copyright 2013 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 "chrome/browser/ui/webui/chromeos/first_run/first_run_handler.h"
 
 #include "base/bind.h"
+#include "base/memory/ptr_util.h"
 #include "base/values.h"
 #include "content/public/browser/web_ui.h"
 
 namespace chromeos {
 
 FirstRunHandler::FirstRunHandler()
     : is_initialized_(false),
       is_finalizing_(false) {
 }
 
@@ skipping 25 matching lines @@
 void FirstRunHandler::ShowStepPositioned(const std::string& name,
                                          const StepPosition& position) {
   web_ui()->CallJavascriptFunctionUnsafe(
       "cr.FirstRun.showStep", base::Value(name), *position.AsValue());
 }
 
 void FirstRunHandler::ShowStepPointingTo(const std::string& name,
                                          int x,
                                          int y,
                                          int offset) {
-  std::unique_ptr<base::Value> null = base::Value::CreateNullValue();
+  auto null = base::MakeUnique<base::Value>();
   base::ListValue point_with_offset;
   point_with_offset.AppendInteger(x);
   point_with_offset.AppendInteger(y);
   point_with_offset.AppendInteger(offset);
   web_ui()->CallJavascriptFunctionUnsafe(
       "cr.FirstRun.showStep", base::Value(name), *null, point_with_offset);
 }
 
 void FirstRunHandler::HideCurrentStep() {
   web_ui()->CallJavascriptFunctionUnsafe("cr.FirstRun.hideCurrentStep");
@@ skipping 60 matching lines @@
     delegate()->OnStepHidden(step_name);
 }
 
 void FirstRunHandler::HandleFinalized(const base::ListValue* args) {
   is_finalizing_ = false;
   if (delegate())
     delegate()->OnActorFinalized();
 }
 
 }  // namespace chromeos