Iteratively increase sample size for good/bad classification.

scripts/slave/recipes/bisect.expected/broken_good_revision_test.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "tryserver.chromium.perf",
       "--builder",
       "linux_perf_bisector",
@@ skipping 487 matching lines @@
     "cwd": "[SLAVE_BUILD]",
     "name": "Gathering reference values.Triggering test job for 306475",
     "trigger_specs": [
       {
         "builder_name": "linux_perf_tester",
         "properties": {
           "bisect_config": {
             "command": "tools/perf/run_benchmark -v --browser=release page_cycler.intl_ar_fa_he",
             "max_time_minutes": "5",
             "metric": "warm_times/page_load_time",
-            "repeat_count": "2",
+            "repeat_count": 3,
             "test_type": "perf"
           },
           "job_name": "e28dc0d49c331def2a3bbf3ddd0096eb51551155-test",
           "parent_build_archive_url": "gs://chrome-perf/Linux Builder/full-build-linux_e28dc0d49c331def2a3bbf3ddd0096eb51551155.zip",
           "parent_got_revision": "e28dc0d49c331def2a3bbf3ddd0096eb51551155",
           "revision": "e28dc0d49c331def2a3bbf3ddd0096eb51551155"
         }
       }
     ],
     "~followup_annotations": [
@@ skipping 22 matching lines @@
     "cwd": "[SLAVE_BUILD]",
     "name": "Gathering reference values.Triggering test job for src@a6298e4afedbf2cd461755ea6f45b0ad64222222",
     "trigger_specs": [
       {
         "builder_name": "linux_perf_tester",
         "properties": {
           "bisect_config": {
             "command": "tools/perf/run_benchmark -v --browser=release page_cycler.intl_ar_fa_he",
             "max_time_minutes": "5",
             "metric": "warm_times/page_load_time",
-            "repeat_count": "2",
+            "repeat_count": 3,
             "test_type": "perf"
           },
           "job_name": "a6298e4afedbf2cd461755ea6f45b0ad64222222-test",
           "parent_build_archive_url": "gs://chrome-perf/Linux Builder/full-build-linux_a6298e4afedbf2cd461755ea6f45b0ad64222222.zip",
           "parent_got_revision": "a6298e4afedbf2cd461755ea6f45b0ad64222222",
           "revision": "a6298e4afedbf2cd461755ea6f45b0ad64222222"
         }
       }
     ],
     "~followup_annotations": [
@@ skipping 151 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@shutil.copyfileobj(open(sys.argv[1]), sys.stdout)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]