Revert of Parallel cache - preliminary  (patchset #22 id:420001 of https://codereview.chromium.org/1264103003/ )

Reason for revert:
Seems to freeze android devices.

Original issue's description:
> Parallel cache.
>
> TBR=reed@google.com
>
> BUG=skia:1330
>
> Committed: https://skia.googlesource.com/skia/+/6f2a486040cb25465990196c229feb47e668e87f

TBR=reed@google.com,mtklein@google.com,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:1330

Review URL: https://codereview.chromium.org/1327703003
9 files changed