This should fix a null D3D11 backend draw call performance regression.

BUG=651101

Change-Id: I2eb10cddd15f0e7b25b886c89eccd2906e988c72
Reviewed-on: https://chromium-review.googlesource.com/392227Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>