Rename gl::Shader::Data to gl::ShaderState. BUG=angleproject:1363 Change-Id: I49cb5d7319742487c8c00c58ec58f9a29561b9c1 Reviewed-on: https://chromium-review.googlesource.com/340743 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>