Fennec already implements a permissions DB for web apps. We need this in Gecko proper so we can use it in Firefox as well. This needs some minimal UI that allows the user to grant permissions when they are first requested, and an API so that permissions can be queried and pre-populated at install time (if the user clicks on the permissions requested).

We need to think a bit about what this means for B2G. We probably want a full screen grayed out security dialog or something like that.

What permissions are we going to synchronously force users to decide on? Or are you talking about the install dialog.

Fennec doesn't have a dedicated DB for this. It just uses the install dialog as a way to allow the user to preset some permissions for the app. Permissions are stored in the permission manager. This is a UX issue only, and we don't need to force the user to do anything. Permissions needed and not granted when installing will be ask on the fly later.