Distinguish common and unique names for skiaperf.com.

Turns out we tack on the size post-facto in ResultsWriter::bench(), so the only
place we need getUniqueName() to differ from getName() is SKPBench.

BUG=skia:
R=jcgregorio@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/552303004
5 files changed