Where does PERSISTENT file system storage store with chrome?

When doing webkitRequestFileSystem in window.PERSISTENT option in Google Chrome, where on my filesystem do files get written? I'd like to drop files there and have Chrome interact with them while I'm building and debugging this app.

For me, at least on Mac OSX, they're stored under /Users/USERNAME/Library/Application Support/Google/Chrome/Default/File System for me. If you're using profiles, there will be profile directories instead of Default. However, each origin's saved files/folders are obfuscated under directories that won't be easy for you to interact with.

For debugging the Filesystem API, you have a few options:

1. Use this extension to view/remove files.
2. See the tips here: http://updates.html5rocks.com/2011/08/Debugging-the-Filesystem-API That includes viewing stored files very easily using the filesystem: URLs.
3. Drop the Filesystem Playground demo (http://html5-demos.appspot.com/static/filesystem/filer.js/demos/index.html) into your origin. You can use that to view/rename/delete files/folders easily.
4. Chrome DevTools now has support for the Filesystem API for viewing the files stored under an origin. To use that, you will need to enable the Developer Tools experiments in about:flags, restart, hit the gear in the devtools (lower right corner), and enable the 'FileSystem inspection' under the experimental tab.