Hi, sorry for the delayed reply.
Regarding the RPC API, I made a rough timeline (available in my proposal) and like you said that I couldn't fit the RPC API part. So, I focused primarily on Nautilus and Epiphany integration and moved RPC to post-GSoC work.
Now about the major point of transfer of state/cookies to libtransfers. I don't think it would be a problem with Nautilus integration but it will be a major component of Epiphany integration. So before I update my proposal with how it will be implemented, I wish to discuss it more.
From epiphany source, here's what I could figure out so far. (w.r.t downloads, also pardon me if my understanding is flawed).
--- ephy-download.c/h ----
The basic object for download is EphyDownload.
ephy_download_start() is the function call to download. It checks the download object, sets start time and destination and calls the webkit_download_start() function on the WebkitDownload object associated with the EphyDownload object.
---- Webkit2 API ----
WebkitDownload object handles the download in Webkit2. Using webkit_download_get_web_view() the WebkitWebView object that started the download can be obtained whose WebkitContext can be obtained fromwebkit_web_view_get_context(). This object can be used to retrieve the WebkitCookieManager corresponding to this context.
Now here, I get stuck as I am not able to find a way to retrieve cookies corresponding to this download. If it can be retrieved, it can be passed in an organised manner to the transfers daemon.
Any suggestions/help?