move skpipe to experimental

Nothing's using it except test tools.
I'd like to make that a bit clearer by getting it out of src.

Disabled the fuzzer.

Removed the bench so Android's building nanobench doesn't block this.

Bug: chromium:886713

Change-Id: I761f52c40171c27ff4b699409b32647e84684ec3
Reviewed-on: https://skia-review.googlesource.com/156240
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
13 files changed