GitLab

Following the PSA for API deprecations, the following are removed:

 - GPUDevice.createBufferMapped
 - GPUBuffer.mapReadAsync
 - GPUBuffer.mapWriteAsync

Also a small check in ValidateRange is fixed.

Bug: dawn:22
Change-Id: I390b9992683e660fece3a17e0671149a40efcd1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351971
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799762}