Metal: fix memory leaks in Texture::getStencilView The leaks were because we stored a strong ref to the texture itself in mStencilView member if the texture already has a stencil format. This caused a circular reference preventing the texture from being released. This indirectly caused MSRTT's memory leaks in chromium:374072906 due to MSRTT using getStencilView for blitting step. Bug: chromium:374072906 Change-Id: I8ced300c2da2de1282c623780dd1affd9d45fb05 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5937060 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org> Commit-Queue: Quyen Le <lehoangquyen@chromium.org> Auto-Submit: Quyen Le <lehoangquyen@chromium.org>