Pass mb_mastername and mb_buildername as parameters to override the default.

scripts/slave/recipe_modules/perf_try/api.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """API for the perf try job recipe module.
 
 This API is meant to enable the perf try job recipe on any chromium-supported
 platform for any test that can be run via buildbot, perf or otherwise.
 """
 
@@ skipping 164 matching lines @@
       self.m.chromium_android.clean_local_files()
       compile_targets = None
     else:
       # Removes any chrome temporary files or build.dead directories.
       self.m.chromium.cleanup_temp()
 
     if 'With Patch' in name:
       self.m.chromium_tests.transient_check(
           update_step,
           lambda transform_name: self.m.chromium_tests.run_mb_and_compile(
-              compile_targets, None, name_suffix=transform_name('')))
+              compile_targets, None, name_suffix=transform_name(''),
+              mb_mastername=mastername, mb_buildername=buildername))
     else:
       self.m.chromium_tests.run_mb_and_compile(
-          compile_targets, None, name_suffix=' %s' % name)
+          compile_targets, None, name_suffix=' %s' % name,
+          mb_mastername=mastername, mb_buildername=buildername)
 
   def _run_test(self, cfg, **kwargs):
     """Runs test from config and return results."""
     values, overall_output, retcodes = self.m.bisect_tester.run_test(
         cfg, **kwargs)
     all_values = self.m.bisect_tester.digest_run_results(values, retcodes, cfg)
     overall_success = True
     if (not kwargs.get('allow_flakes', True) and
         cfg.get('test_type', 'perf') != 'return_code'):
       overall_success = all(v == 0 for v in retcodes)
@@ skipping 243 matching lines @@
 
 def _prepend_src_to_path_in_command(test_cfg):
   command_to_run = []
   for v in test_cfg.get('command').split():
     if v in ['./tools/perf/run_benchmark',
              'tools/perf/run_benchmark',
              'tools\\perf\\run_benchmark']:
       v = 'src/tools/perf/run_benchmark'
     command_to_run.append(v)
   test_cfg.update({'command': ' '.join(command_to_run)})