Revert of Revert of Force DM rebuild. (https://codereview.chromium.org/399123002/)

Revert of Revert of Force DM rebuild. (https://codereview.chromium.org/399123002/)

Reason for revert:
jkl;

Original issue's description:
> Revert of Force DM rebuild. (https://codereview.chromium.org/400723002/)
>
> Reason for revert:
> asdf
>
> Original issue's description:
> > Force DM rebuild.
> >
> > BUG=skia:
> >
> > Committed: https://skia.googlesource.com/skia/+/8a10de1
>
> TBR=mtklein@chromium.org
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/f42e08c12533f2a165bc08451f5ab5dd1363618b

R=mtklein@chromium.org
TBR=mtklein@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/402663003