Ensure ValidateGetMemoryObjectParameter entry point consistency Invalid calls must not reach the context. Bug: angleproject:406922380 Change-Id: I6b4fadabe93215839fcd6c8d35952f37d5a6755b Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6417007 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com>