Password manager should work in iframes
Currently the password manager does not work on reddit.com because we run Ephy JS only in the main frame, never in iframes, but the login form on reddit is an iframe. What a shame! Let's change this.
It requires a new webkit_frame_get_id() API to be able to track frames across the process boundary, and also a new form-controls-associated-for-frame signal since sadly we can't add new parameters to signals without breaking API.
Note: WIP because I haven't landed the new WebKit APIs yet
Edited by Michael Catanzaro