Change the NSGL skeleton to be a CGL skeleton The previous skeleton was name NSGL because it seemed the easier route to go, however Chrome uses CGL internally, which we want to match. BUG=angleproject:891 Change-Id: I00eb597080c8b735545750dfcd6ad80dcea79300 Reviewed-on: https://chromium-review.googlesource.com/289870 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Corentin Wallez <cwallez@chromium.org>