Destroy can be used to free the GPU memory associated with resources
without waiting for javascript garbage collection to occur.
The buffer is validated at submission to the queue.
So any buffer that has been destroyed before submission, will then
invalidate the submit and result in an error.
Bug: dawn:46
Change-Id: I40df56ce97baef01deea7552d7a6d40b558fc985
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/5320
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Natasha Lee <natlee@microsoft.com>