Indexed DB: Remove vendor prefix removal from tests

LayoutTests/storage/indexeddb/transaction-after-close-expected.txt

 Test closing a database connection in IndexedDB.
 
 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 = "transaction-after-close.html"
 indexedDB.deleteDatabase(dbname)
 indexedDB.open(dbname)
 store = db.createObjectStore('store')
 request = store.put('x', 'y')
 PASS Put success
 running first transaction
 currentTransaction = db.transaction(['store'], 'readwrite')
 objectStore.put('a', 'b')
 db.close()
 Expecting exception from db.transaction(['store'], 'readwrite')
 PASS Exception was thrown.
 PASS code is DOMException.INVALID_STATE_ERR
 PASS ename is 'InvalidStateError'
 Exception message: Failed to execute 'transaction' on 'IDBDatabase': The database connection is closing.
 
 verify that we can reopen the db after calling close
 indexedDB.open(dbname)
 second_db = event.target.result
 currentTransaction = second_db.transaction(['store'], 'readwrite')
 request = store.put('1', '2')
 PASS final put success
 PASS successfullyParsed is true
 
 TEST COMPLETE