Indexed DB: Remove vendor prefix removal from tests

LayoutTests/storage/indexeddb/dont-commit-on-blocked-expected.txt

 Regression test for WK82678 - don't commit after a blocked event
 
 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 = "dont-commit-on-blocked.html"
 indexedDB.deleteDatabase(dbname)
 indexedDB.open(dbname)
 db.onversionchange = onVersionChange
 store = db.createObjectStore('store1')
 
 holdConnection():
 holding connection until versionchange event
 
 Starting worker: resources/dont-commit-on-blocked-worker.js
-[Worker] indexedDB = self.indexedDB || self.webkitIndexedDB || self.mozIndexedDB || self.msIndexedDB || self.OIndexedDB;
-[Worker] 
 [Worker] opening database connection
 [Worker] request = indexedDB.open('dont-commit-on-blocked.html', 2)
 [Worker] state = 'setversion'
 [Worker] request.onblocked = onSetVersionBlocked
 [Worker] request.onupgradeneeded = onSetVersionSuccess
 [Worker] spinning for 100ms to let events be queued but prevent dispatch
 [Worker] done spinning
 [Worker] 
 [Worker] onSetVersionBlocked():
 PASS [Worker] state is "setversion"
 [Worker] state = 'blocked'
 [Worker] 
 [Worker] onSetVersionSuccess():
 [Worker] db = event.target.result
 PASS [Worker] state is "blocked"
 [Worker] state = 'success'
 [Worker] creating object store - will fail if transaction commited after blocked event
 [Worker] db.createObjectStore('store2')
 [Worker] 
 [Worker] onTransactionComplete
 PASS [Worker] state is "success"
 PASS [Worker] Number(db.version) is 2
 PASS [Worker] db.objectStoreNames.contains('store1') is true
 PASS [Worker] db.objectStoreNames.contains('store2') is true
 PASS successfullyParsed is true
 
 TEST COMPLETE