Inherit privately from angle::NonCopyable. Make all inheritance from angle::NonCopyable private so the compiler complains about this (admittedly unlikely) code: class Foo: angle::NonCopyable { virtual ~Foo() { ... } }; angle::NonCopyable *p = new Foo; delete p; In the above code ~Foo() is not called, only ~NonCopyable(), because the latter is not virtual. Making it virtual would add overhead to all derived classes which don't already have a virtual method. Also tighten access in NonCopyable, because we can. BUG=angleproject:2026 Change-Id: Id0dc4d959cfb7bb82cf49382118129abb1d3a4f0 Reviewed-on: https://chromium-review.googlesource.com/495352 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Frank Henigman <fjhenigman@chromium.org>