GLContextEGL is now the only implementation of GLContext, so there's no reason to have a base abstract class.
Pull request: https://github.com/WebKit/WebKit/pull/11806
Committed 262074@main (e322dc6f4a14): <https://commits.webkit.org/262074@main> Reviewed commits have been landed. Closing PR #11806 and removing active labels.
<rdar://problem/107187445>