Change more base::ListValue methods to use std::unique_ptr.

chrome/browser/notifications/notifier_state_tracker.cc

 // Copyright 2015 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/notifications/notifier_state_tracker.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 126 matching lines @@
 #endif
       break;
     default:
       NOTREACHED();
   }
   DCHECK(pref_name != NULL);
 
   ListPrefUpdate update(profile_->GetPrefs(), pref_name);
   base::ListValue* const list = update.Get();
   if (add_new_item) {
-    // AppendIfNotPresent will delete |adding_value| when the same value
-    // already exists.
-    list->AppendIfNotPresent(id.release());
+    list->AppendIfNotPresent(std::move(id));
   } else {
-    list->Remove(*id, NULL);
+    list->Remove(*id, nullptr);
   }
 }
 
 void NotifierStateTracker::OnStringListPrefChanged(
     const char* pref_name, std::set<std::string>* ids_field) {
   ids_field->clear();
   // Separate GetPrefs()->GetList() to analyze the crash. See crbug.com/322320
   const PrefService* pref_service = profile_->GetPrefs();
   CHECK(pref_service);
   const base::ListValue* pref_list = pref_service->GetList(pref_name);
@@ skipping 36 matching lines @@
   // Tell the IO thread that this extension's permission for notifications
   // has changed.
   extensions::InfoMap* extension_info_map =
       extensions::ExtensionSystem::Get(profile_)->info_map();
   content::BrowserThread::PostTask(
       content::BrowserThread::IO, FROM_HERE,
       base::Bind(&extensions::InfoMap::SetNotificationsDisabled,
                  extension_info_map, notifier_id.id, !enabled));
 }
 #endif