IndexedDB user's feedback

Hello

I ask you about some new functions in IndexedDB API, which
are extremely needed:
1. How much space available for adding
2. Request user for more space
As I know now limit for IndexedDB in most browsers is about 50 Mb, but it
is not possible to know how much space used, so how much place still.
Adding this functions would be extremely useful.

Regards,
Alex Abramov