Indexed DB: Remove vendor prefix removal from tests

LayoutTests/storage/indexeddb/mozilla/remove-objectstore-expected.txt

 Test IndexedDB deleting an object store
 
 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 = "remove-objectstore.html"
 indexedDB.deleteDatabase(dbname)
 indexedDB.open(dbname)
 PASS db.objectStoreNames.length is 0
 objectStoreName = 'Objects';
 objectStore = db.createObjectStore(objectStoreName, { keyPath: 'foo' });
 request = objectStore.add({foo: i});
 request = objectStore.add({foo: i});
 request = objectStore.add({foo: i});
 request = objectStore.add({foo: i});
@@ skipping 108 matching lines @@
 PASS db.objectStoreNames.length is 0
 db.close()
 request = indexedDB.open(dbname, 3)
 objectStore = db.createObjectStore(objectStoreName, { keyPath: 'foo' });
 request = objectStore.add({foo:'bar'});
 db.deleteObjectStore(objectStoreName);
 PASS successfullyParsed is true
 
 TEST COMPLETE