Chrome has started requesting RGB formats for IOSurfaces to support the alpha=false flag for WebGL context creation. BUG=chromium:995142 Change-Id: I0c9d994f2d8208e87a0d167ebc0787fc15add08f Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/35389Reviewed-by: Nicolas Capens <nicolascapens@google.com> Tested-by: Geoff Lang <geofflang@chromium.org>
