Vulkan: Destroy fb1 should not affect fb2 with same attachments If two FBOs has the same attachments. they will share the same VkFramebuffers. Destroy one fbo should not cause trouble for the other fbo. Bug: chromium:1351170 Change-Id: I032da8cc12eb8556c3e325c8fd7a3de9974ae909 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3824302 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Yuxin Hu <yuxinhu@google.com> Commit-Queue: Charlie Lao <cclao@google.com>