Fix small bugs with non-autotest Telemetry; other cleanups.

This CL fixes various small problems found during recent testing:
- Force show_all_results to be true for 'pure' telemetry case (the
results filtering needs the autotest results to work properly)
- Fix bug that was inserting extra 'src' into Chrome src path sometimes
- Since non-autotest Telemetry and non-Telemetry-Crosperf tests can't
handle 'perf' make it a Fatal error to call them with perf args.
- Add missing field to example experiment file.
- Add status output messages to downlaod_images.py for non-verbose logging.

BUG=None
TEST=Tested all these fixes on multiple test runs.

Change-Id: If8209356c695dc8b21f8627399a1cbd4a858df23
Reviewed-on: https://chrome-internal-review.googlesource.com/161759
Reviewed-by: Yunlian Jiang <yunlian@google.com>
Commit-Queue: Caroline Tice <cmtice@google.com>
Tested-by: Caroline Tice <cmtice@google.com>
5 files changed