Don't upload expectations if there isn't any bench data
Don't upload expectations if there isn't any bench data

BUG=skia:
R=bensong@google.com, jcgregorio@google.com, borenet@google.com

Author: kelvinly@google.com

Review URL: https://codereview.chromium.org/359653002

google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot