Revert of Move BenchTimer to tools as Timer (https://codereview.chromium.org/344213003/)

Reason for revert:
GpuTimer broken

Original issue's description:
> Move BenchTimer to tools as Timer
>
> This breaks a bunch of circular dependencies between tools and gm and bench.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/4ed75287aed6371c6e4a41ffcc78c8a49c9810ed

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

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/346753003
44 files changed