Delete osWindow and eglWindow in ReleaseFixtures valgrind rightfully reports these as leaks Bug: b/258723409 Change-Id: I02dbd771c6f7bd9e7df2269c77d8bd95af593044 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4025992 Auto-Submit: Roman Lavrov <romanl@google.com> Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: Roman Lavrov <romanl@google.com>