Use [[nodiscard]] on RAII classes Scoped* classes provide an RAII way of adding cleanup/restore state/etc in a robust way. Unfortunatley, it's very easy to mistakenly leave the variable name, leading to the destructor being called immediately instead of at the end of the scope: { ScopedX(parameters); // instead of ScopedX x(parameters); // Code here is run after destructor } The [[nodiscard]] attribute, if specified on the ScopedX class would lead to a warning (turned to error with -Werror). This change does that for classes named *Scoped* in ANGLE. Bug: chromium:1103817 Change-Id: I65c9922c9b4eba1f9c033e093fe8fe534648ab62 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3552092 Reviewed-by: Lingfeng Yang <lfy@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>