IndexedDB: Log exception messages

LayoutTests/storage/indexeddb/version-change-exclusive-expected.txt

 Ensure pending open waits for version change transaction to complete.
 
 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 = "version-change-exclusive.html"
 indexedDB.deleteDatabase(dbname)
 indexedDB.open(dbname)
 calling open() - callback should wait until VERSION_CHANGE transaction is complete
 indexedDB.open(dbname)
 setVersion() callback
 starting work in VERSION_CHANGE transaction
 self.state = 'VERSION_CHANGE started'
 store = db.createObjectStore('test-store')
 Expecting exception from db.transaction('test-store')
 PASS Exception was thrown.
 PASS code is DOMException.INVALID_STATE_ERR
 PASS ename is 'InvalidStateError'
+Exception message: A version change transaction is running.
 store.put(0, 0)
 in put's onsuccess
 store.put(1, 1)
 in put's onsuccess
 store.put(2, 2)
 in put's onsuccess
 store.put(3, 3)
 in put's onsuccess
 store.put(4, 4)
 in put's onsuccess
 store.put(5, 5)
 in put's onsuccess
 store.put(6, 6)
 in put's onsuccess
 store.put(7, 7)
 in put's onsuccess
 store.put(8, 8)
 in put's onsuccess
 store.put(9, 9)
 in put's onsuccess
 ending work in VERSION_CHANGE transaction
 self.state = 'VERSION_CHANGE finished'
 open() callback - this should appear after VERSION_CHANGE transaction ends
 PASS self.state is "VERSION_CHANGE finished"
 PASS successfullyParsed is true
 
 TEST COMPLETE