Use Gecko as HTTP client for Glean

[pocmo]

I saw that we are initializing Glean with the default client - which means it will be using HttpUrlConnection.

In AC we have an adapter that wraps GeckoView and will use Gecko instead of HttpUrlConnection. This is what Fenix is using as well. I assume that is something Firefox Reality would want too.

There are two options:

• Use the Client implementation from AC. However since Firefox Reality and AC are not synchronized on GeckoView versions this could cause breakage if the API in GeckoView changes in a breaking way.
• Add a simple Client implementation wrapping GeckoView directly to Firefox Reality. Even in AC the code is minimal: https://github.com/mozilla-mobile/android-components/blob/master/components/browser/engine-gecko/src/main/java/mozilla/components/browser/engine/gecko/fetch/GeckoViewFetchClient.kt

[pocmo]

If you agree that this is worthwhile then I can try writing a patch for this. :)

[pocmo]

Just saw that there's already a GeckoViewFetchClient in the repo. So we could just use that!

https://github.com/MozillaReality/FirefoxReality/blob/master/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/GeckoViewFetchClient.kt

[keianhzo]

Thanks @pocmo! Yes, we are already using the GeckoWebExecutor everywhere, I think this was missing because the default Glean configuration used HttpUrlConnection. This should be addressed by #3498 as we migrate to AC 44 there and it forced us to do so.

[pocmo]

Yeah, afaik in the lastest AC version we will require you to explicitly pass in a client.