crosperf: fix lint warnings.

BUG=chromium:570454
TEST=unittest passes, lint warning is gone.

Change-Id: I4801d560990ad2ed20e30d5cefd5f1ec2c6c5a3d
Reviewed-on: https://chrome-internal-review.googlesource.com/243408
Commit-Ready: Yunlian Jiang <yunlian@google.com>
Tested-by: Yunlian Jiang <yunlian@google.com>
Reviewed-by: Yunlian Jiang <yunlian@google.com>
3 files changed