git_hosting_providers: Add support for Chromium repositories

[hferreiro]

Add an implementation of GitHostingProvider for repositories hosted on https://chromium.googlesource.com. Pull requests target the Gerrit instance at https://chromium-review.googlesource.com and avatar images are fetched using the Gerrit REST API.

Release Notes:

• Added support for repositories hosted on chromium.googlesource.com for Git blames and permalinks.

[hferreiro]

@maxdeviant hey! This PR just has one thing missing. The avatar url at https://github.com/zed-industries/zed/pull/24881/files#diff-0296a250f68527abab595c466384867f70c35cf6052ac77a281fe72941654b27R187 doesn't return an image but an HTTP 302 that points to the actual image. Can you give a hint on how to make that work?

[maxdeviant]

@maxdeviant hey! This PR just has one thing missing. The avatar url at https://github.com/zed-industries/zed/pull/24881/files#diff-0296a250f68527abab595c466384867f70c35cf6052ac77a281fe72941654b27R187 doesn't return an image but an HTTP 302 that points to the actual image. Can you give a hint on how to make that work?

The avatar URLs seem to load for me:

I think we can go ahead and merge this.

[hferreiro]

Yeah, for some reason it didn't work before. Maybe it took some time to load, and I just gave up 🤷

[maxdeviant]

Yeah, for some reason it didn't work before. Maybe it took some time to load, and I just gave up 🤷

While debugging it I noticed two things:

1. In the repositories I was testing with, some of the older commits had dead links, which meant we couldn't retrieve the author information to construct the avatar URL.
2. It did take a few seconds to load in the first time.

[maxdeviant]

Thank you!

[hferreiro]

In the repositories I was testing with, some of the older commits had dead links

Do you have some of those at hand?

[maxdeviant]

In the repositories I was testing with, some of the older commits had dead links

Do you have some of those at hand?

Hmm, odd, I'm not seeing the dead links anymore!

[hferreiro]

What I had more doubts about this was to either rely on Reviewed-On or Change-Id. The latter should be more reliable and other Gerrit projects not hosted at https://chromium.googlesource.com/ only use that but the issue with it is that multiple "PRs" can have the same Change-Id.

I can revisit this in the future though.