Narrow clear-as-draw workaround on D3D11 ANGLE

Bug: skia:
Change-Id: Ib2714b448b078a09d43a28fd5bd7329706b516b8
Reviewed-on: https://skia-review.googlesource.com/c/188310
Commit-Queue: Robert Phillips <robertphillips@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
3 files changed