Change navigator.gpu.getAdapter to navigator.gpu.requestAdapter.

This function now returns a Promise instead of getting an adapter
synchronously. GPUAdapterDescriptor is renamed to GPURequestAdapterOptions.

Bug: 941531
Change-Id: If8a996fe15adc6301f7378ce15f084cba1ae2601
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1521235
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641061}
5 files changed