Workspaces feature doesn't work.

The Workspaces feature doesnt work, as it relies on access to the local filesystem.

It looks like the filesystem implementation in DevTools doesn't use the remote debugging protocol, but some magical logic that get's injected at runtime,

Actions:
- [ ] Figure out how the filesystem functionality is implemented
- [ ] Emulate behavior in node-webkit.

Start by tracing how filesystem functionality is implemented in DevTools and how the remote debugging protocol is involved. Then investigate how the behavior should be emulated in node-webkit; done means the Workspaces feature works without relying on unavailable local-filesystem access.

Written by the indexing model from the issue text.