Indexed DB: Remove vendor prefix removal from tests

LayoutTests/storage/indexeddb/mozilla/autoincrement-indexes-expected.txt

 Test IndexedDB indexes against autoincrementing keys
 
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
 
-indexedDB = self.indexedDB || self.webkitIndexedDB || self.mozIndexedDB || self.msIndexedDB || self.OIndexedDB;
-
 dbname = "autoincrement-indexes.html"
 indexedDB.deleteDatabase(dbname)
 indexedDB.open(dbname)
 objectStore = db.createObjectStore('autoincrement-id', { keyPath: 'id', autoIncrement: true });
 objectStore.createIndex('first', 'first');
 objectStore.createIndex('second', 'second');
 objectStore.createIndex('third', 'third');
 data = { first: 'foo', second: 'foo', third: 'foo' };
 request = objectStore.add(data);
 key = event.target.result;
 PASS key == null is false
 expected key is 1
 objectStore = db.transaction('autoincrement-id').objectStore('autoincrement-id');
 first = objectStore.index('first');
 request = first.get('foo');
 PASS event.target.result.id is key
 second = objectStore.index('second');
 request = second.get('foo');
 PASS event.target.result.id is key
 third = objectStore.index('third');
 request = third.get('foo');
 PASS event.target.result.id is key
 PASS successfullyParsed is true
 
 TEST COMPLETE