Fix D3D dynamic buffer reuse.

This is a temporary fix to handle an issue where we try to map a
dynamic buffer when it's in use in a previous command list.

Change-Id: Ibc6b071508c11ea394a320b326645ecc4b22105a
Bug: skia:9935
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/299392
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
2 files changed