Run commandbuffer config on CommandBuffer Perf bots.

Uh, so hey, I just noticed that while the CommandBuffer Test bot runs
with --config commandbuffer, the Perf bot just runs as a vanilla GPU bot.
Shouldn't we pass --config commandbuffer?

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2364483002

CQ_INCLUDE_TRYBOTS=master.client.skia:Perf-Mac-Clang-MacMini6.2-GPU-HD4000-x86_64-Debug-CommandBuffer-Trybot

Review-Url: https://codereview.chromium.org/2364483002
2 files changed