Ensure ValidateLoseContextCHROMIUM entry point consistency Invalid calls must not reach the context. Bug: angleproject:406922380 Change-Id: I5d0d74ea28ae16efba1bd447f6187a36c05c45c7 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6417008 Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>