[test] Add flag for concurrent-marking trybot to try_perf

NOTRY=true
TBR=ulan@chromium.org

Bug: chromium:735951
Change-Id: Ic5cf6692988ede915aabdc1c44eea52b42bf7f45
Reviewed-on: https://chromium-review.googlesource.com/547426Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46199}

tools/try_perf.py

@@ -14,6 +14,7 @@ BOTS = {
   '--linux64': 'v8_linux64_perf_try',
   '--linux64_atom': 'v8_linux64_atom_perf_try',
   '--linux64_haswell': 'v8_linux64_haswell_perf_try',
+  '--linux64_haswell_cm': 'v8_linux64_haswell_cm_perf_try',
   '--nexus5': 'v8_nexus5_perf_try',
   '--nexus7': 'v8_nexus7_perf_try',
   '--nexus9': 'v8_nexus9_perf_try',