IndexedDB: Stop using webkit-prefixed versions of APIs in tests

content/test/data/indexeddb/migration_test.js

 // Copyright (c) 2012 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.
 
 function test() {
-  request = webkitIndexedDB.open('open-close-version-test1');
+  request = indexedDB.open('open-close-version-test1');
   request.onsuccess = openTest2;
   request.onerror = unexpectedErrorCallback;
   request.onblocked = unexpectedBlockedCallback;
 }
 
 function openTest2(event) {
   db = event.target.result;
   debug("Ensure that the existing leveldb files are used. If they are not, " +
         "this script will create a new database that has no object stores");
   shouldBe("db.objectStoreNames.length", "1");
   shouldBeEqualToString("typeof db.version", "string");
-  request = webkitIndexedDB.open('open-close-version-test2');
+  request = indexedDB.open('open-close-version-test2');
   request.onsuccess = done;
   request.onerror = unexpectedErrorCallback;
   request.onblocked = unexpectedBlockedCallback;
 }