WebApps and permission list?

I have a question about WebApps manifests and permissions. The page is
part of Manifest for Web Applications located at
http://www.w3.org/2012/sysapps/manifest/. The document provides a
permission member and the following description:

    The permissions localizable member is a permissions
    object that represents a list of permissions that the
    application requires to function.

Is there a list of permissions or capabilities available (or expected
to be made available)?

Will users be able to selectively grant/revoke permissions (for
example, similar to Apple's model)? Or will they be an all-or-nothing
proposition (similar to Google's model)?

When are permissions granted? At runtime (for example, similar to
Apple's model)? Or will they be at install time (similar to Google's
model)?

Where does the access check occur? In the browser? In the platform?
Perhaps both?

Thanks in advance.

Received on Saturday, 31 May 2014 07:12:44 UTC