Adds the ability to create an es3 command buffer context, but does not
yet begin testing it because libcommand_buffer_gles2.dylib needs to be
updated first to respect the EGL_CONTEXT_CLIENT_VERSION attrib. Adds a
version check on the context as well to verify we actually get an es3
context when we ask for one.
Bug: chromium:1220246
Change-Id: I996f482d8ad831b81f873e1bfd2f0526e5f1e73e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/419616
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
e0f4de6f23