Temporary fix for Angle trybots.

scripts/slave/recipes/bisection/desktop_bisect.expected/perf_cq_no_changes.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport sys, os\npath = sys.argv[1]\nmode = int(sys.argv[2])\nif not os.path.isdir(path):\n  if os.path.exists(path):\n    print \"%s exists but is not a dir\" % path\n    sys.exit(1)\n  os.makedirs(path, mode)\n",
       "[BUILDER_CACHE]/linux_perf_bisect",
       "511"
     ],
     "name": "makedirs checkout path",
@@ skipping 32 matching lines @@
       "--issue",
       "12345",
       "--patchset",
       "20001",
       "--rietveld_server",
       "https://codereview.chromium.org",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@HEAD",
-      "--output_manifest"
+      "--output_manifest",
+      "--gerrit_no_rebase_patch_ref"
     ],
     "cwd": "[BUILDER_CACHE]/linux_perf_bisect",
     "env": {
       "GCLIENT_KILL_GIT_FETCH_AFTER": "1200",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ skipping 192 matching lines @@
     "~followup_annotations": [
       "@@@STEP_TEXT@There are no modifications to Telemetry benchmarks, aborting the try job.@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]