Other small fixes for desktop compatibility

Bug: angleproject:3620
Change-Id: I8e75bce1f850fb891c8bb6e16f79302a6d59276c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1707932
Commit-Queue: Clemen Deng <clemendeng@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>