Change JSON output of nanobench.

We're moving away from BigQuery for storing results so the output doens't have to conform to BQ requirements, which allows simplifying the format. Also stop parsing the filename for information and pass in buildbot parameters explicitly.

Adds the following flags to nanobench:

  --key
  --gitHash

BUG=skia:
R=mtklein@google.com, bsalomon@google.com

Author: jcgregorio@google.com

Review URL: https://codereview.chromium.org/392393002
2 files changed