Convert Service Worker layout tests to W3C testharness-style tests

LayoutTests/virtual/serviceworker/http/tests/serviceworker/indexeddb-expected.txt

-Verify that IndexedDB is functional in a ServiceWorker
 
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+PASS Verify Indexed DB operation in a Service Worker 
 
-
-messageChannel = new MessageChannel()
-messageChannel.port1.onmessage = onMessageHandler
-
-navigator.serviceWorker.register('indexeddb-worker.js')
-serviceWorker.postMessage({port: messageChannel.port2}, [messageChannel.port2])
-[ServiceWorker] Preparing the database in the service worker
-[ServiceWorker] indexedDB.deleteDatabase('db')
-[ServiceWorker] indexedDB.open('db')
-[ServiceWorker] db.createObjectStore('store')
-[ServiceWorker] tx = db.transaction('store', 'readwrite')
-[ServiceWorker] store = tx.objectStore('store')
-[ServiceWorker] store.put('value', 'key')
-
-Verifying the database from the page
-
-request = indexedDB.open('db')
-db = request.result
-tx = db.transaction('store')
-store = tx.objectStore('store')
-request = store.get('key')
-PASS request.result is 'value'
-PASS successfullyParsed is true
-
-TEST COMPLETE
-