Poll for the favicon if it doesn't exist on page load

[niklasbaumgardner]

I unfortunately had to remove the extension from the favicon bucket name in this patch.
But I think this provides a better experience.

[jaredhirsch]

R+ with comments - I've added comments inline for the narrowest possible fixes needed to get the current approach working. Making these changes should be enough to land.

Another approach to consider: we could reduce network traffic by doing the polling at the share page level, not the individual link item level. This would take us from N independent polling loops down to 1. Reducing network traffic reduces server load, but more importantly, reduces battery and data usage on the mobile web. That said I don't think it's strictly necessary to make this change for this service right now--up to you.

[niklasbaumgardner]

Another approach to consider: we could reduce network traffic by doing the polling at the share page level, not the individual link item level. This would take us from N independent polling loops down to 1. Reducing network traffic reduces server load, but more importantly, reduces battery and data usage on the mobile web. That said I don't think it's strictly necessary to make this change for this service right now--up to you.

I ended up just implementing this because it's a good idea. The share object now sends 1 request with all of the urls that need a favicon. The backend takes the urls and returns a dictionary of hostname -> favicon_url