Ensure IDB transactions started before success arrives see correct medata

LayoutTests/storage/indexeddb/metadata-race-expected.txt

+Ensure IndexedDB transactions created before open onsuccess have correct metadata
+
+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 = "metadata-race.html"
+indexedDB.deleteDatabase(dbname)
+indexedDB.open(dbname)
+
+prepareDatabase():
+db = event.target.result
+store = db.createObjectStore('store')
+store.createIndex('index', 'keyPath')
+transaction = event.target.transaction
+PASS index = transaction.objectStore('store').index('index') did not throw exception.
+
+onTransactionComplete():
+In multiprocess mode, 'complete' event may be dispatched before
+the 'success' arrives with updated metadata. Ensure the new metadata
+is still used for transactions.
+store = db.transaction('store').objectStore('store')
+PASS index = store.index('index') did not throw exception.
+
+onOpenSuccess():
+db = event.target.result
+store = db.transaction('store').objectStore('store')
+PASS index = store.index('index') did not throw exception.
+PASS successfullyParsed is true
+
+TEST COMPLETE
+