crosperf: Add generate_report.py.

This script allows us to generate HTML, JSON, text, and email reports
for JSON inputs, rather than needing to run things through crosperf.

BUG=chromium:641098
TEST=cros lint on new files passes, ./run_tests.sh passes.

Change-Id: I213149c0feca8b97f72fb447030c670e2f631a87
Reviewed-on: https://chrome-internal-review.googlesource.com/285238
Commit-Ready: George Burgess <gbiv@google.com>
Tested-by: George Burgess <gbiv@google.com>
Reviewed-by: Caroline Tice <cmtice@google.com>
2 files changed