Selected image can not be displayed when src is file://

[adzialocha]

Selecting an image via runtime.showOpenFileDialog and then displaying the file using the selected path leads to the following error:

GET file:///<path_to_image>.png net::ERR_BLOCKED_BY_CLIENT

This seems to be related to the changes made in 5dfd937

I assume we have to base64 encode the file contents and display this in the element instead to comply with the new restrictions.

[Simon-Laux]

I think the easiest solution would be that runtime.showOpenFileDialog adds the opened path to a temporary whitelist of allowed paths.
There is no core api yet to pass bobs as base64 to core directly. So if we work with base64 we would need to temporarily save the file to the temp folder and then give that path to core (and ideally delete the temp file again after it was copied by core).

[WofWca]

We don't have pass Base64 to core. We could return two things from runtime.showOpenFileDialog: the path (for the core) and the Base64 string (or, perhaps File), for the UI.