If you navigate to https://mdn.mozillademos.org/en-US/docs/Web/API/IndexedDB_API/Using_IndexedDB$samples/Full_IndexedDB_example?revision=798695, the IndexedDB data does not show in the Storage tab. This is likely a bug of some sort with this implementation because IndexedDB does work in other instances, for instance when you inspect Web Inspector.
<rdar://problem/21325445>
[Error] Uncaught exception in inspector page while dispatching callback for command IndexedDB.requestDatabase TypeError: this._addIndexedDatabaseWasAdded is not a function. (In 'this._addIndexedDatabaseWasAdded(event.data.indexedDatabase)', 'this._addIndexedDatabaseWasAdded' is undefined) I'll take a quick look!
Looks like a simple typo. _addIndexedDatabaseWasAdded => _addIndexedDatabase Double checking some more.
Created attachment 254756 [details] [PATCH] Proposed Fix
Comment on attachment 254756 [details] [PATCH] Proposed Fix Clearing flags on attachment: 254756 Committed r185476: <http://trac.webkit.org/changeset/185476>
All reviewed patches have been landed. Closing bug.
Thanks for fixing that, Joe. Woulda done it myself, but #drburg