We were missing the implementation for the instanced draw for these. Implement them in the same way as for triangle fan. BUG=angleproject:1101 Change-Id: I444f3a23383c63b8df6f9ebe25b255c8890632a1 Reviewed-on: https://chromium-review.googlesource.com/313007 Tryjob-Request: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>
