Add validation of null pointers for certain APIs Bug: angleproject:397315932 Change-Id: I3b253a7ca0bbdf4fd55cf67943971426d825cd24 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6275697 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>