This plumbs the front-end code, but doesn't implement Error handling
for any objects yet. Framebuffers and VertexArrays will get error
handling from their syncState methods.

Bug: angleproject:2372
Change-Id: I226049e25ac7af2bdd3c4787b67a5d297c0b9c4b
Reviewed-on: https://chromium-review.googlesource.com/954289
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Luc Ferron <lucferron@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>