S4 Rebaselines

TBR=

Review URL: https://codereview.chromium.org/706653003
Add mock context and use in ResourceCacheTest.

BUG=skia:2889

Review URL: https://codereview.chromium.org/702083003
Turn on NVPR 4x MSAA by default when supported in DM and nanobench.

This brings DM and nanobench's default configs in line with GM's.

BUG=skia:

Review URL: https://codereview.chromium.org/704563003
Revert of Add mock context and use in ResourceCacheTest. (patchset #4 id:60001 of https://codereview.chromium.org/702083003/)

Reason for revert:
Breaking tests

Original issue's description:
> Add mock context and use in ResourceCacheTest.
>
> BUG=skia:2889
>
> Committed: https://skia.googlesource.com/skia/+/820dd6c335411aad889c1d7e8a857642ecd87e30

TBR=robertphillips@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:2889

Review URL: https://codereview.chromium.org/704563004