Add test Pinpoint builder to mb_config.pyl.

tools/mb/mb_config.pyl

 # 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.
 
 # This is a .pyl, or "Python Literal", file. You can treat it just like a
 # .json file, with the following exceptions:
 # * all keys must be quoted (use single quotes, please);
 # * comments are allowed, using '#' syntax; and
 # * trailing commas are allowed.
 
@@ skipping 607 matching lines @@
       'android_nexus7_perf_bisect': 'official_goma_minimal_symbols_android',
       'android_nexus9_perf_bisect': 'official_goma_minimal_symbols_android_arm64',
       'android_one_perf_bisect': 'official_goma_minimal_symbols_android',
       'android_perf_bisect_builder': 'official_goma_minimal_symbols_android',
       'android_s5_perf_bisect': 'official_goma_minimal_symbols_android',
       'android_webview_arm64_aosp_perf_bisect': 'official_goma_minimal_symbols_android',
       'linux_fyi_perf_bisect': 'official_goma',
       'linux_perf_bisect': 'official_goma',
       'linux_perf_bisect_builder': 'official_goma',
       'linux_perf_cq': 'official_goma',
+      'Mac Builder': 'official_goma',
       'mac_10_10_perf_bisect': 'official_goma',
       'mac_10_11_perf_bisect': 'official_goma',
       'mac_fyi_perf_bisect': 'official_goma',
       'mac_hdd_perf_bisect': 'official_goma',
       'mac_perf_bisect_builder': 'official_goma',
       'mac_retina_perf_bisect': 'official_goma',
       'mac_retina_perf_cq': 'official_goma',
       'win_8_perf_bisect': 'official_goma_x86',
       'win_fyi_perf_bisect': 'official_goma_x86',
       'win_perf_bisect': 'official_goma_x86',
@@ skipping 1287 matching lines @@
 
     'x64': {
       'gn_args': 'target_cpu="x64"',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
     },
   },
 }