Update and expand regression tests for results_cache.py

BUG=None
TEST=Ran regression tests successfully.  Ran 'normal' crosperf tests
successfully as well.

Change-Id: Ib3387cb63f1050cc0d561cc676d91be2334e0c79
Reviewed-on: https://chrome-internal-review.googlesource.com/166133
Reviewed-by: Caroline Tice <cmtice@google.com>
Commit-Queue: Caroline Tice <cmtice@google.com>
Tested-by: Caroline Tice <cmtice@google.com>
11 files changed