Rename the new Mac bot.

masters/master.chromium.gpu.fyi/slaves.cfg

 # Copyright (c) 2012 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.
 
 slaves = [
   {
     'master': 'ChromiumGPUFYI',
     'hostname': 'vm80-m1',
     'builder': 'GPU Win Builder',
     'os': 'win',
@@ skipping 352 matching lines @@
     'recipe': 'chromium',
     'build_config': 'Debug',
     # This bot uses recipe-side triggers.
     'triggered_by': 'none',
     # Nearly all bots on these waterfalls are auto-rebooted between
     # runs for stability.
   },
   {
     'master': 'ChromiumGPUFYI',
     'hostname': 'build52-b1',
-    'builder': 'Mac Retina Release (AMD)',
+    'builder': 'Mac 10.11 Retina Release (AMD)',
     'os': 'mac',
     'version': '10.11',
     'bits': '64',
     'recipe': 'chromium',
     'build_config': 'Release',
     # This bot uses recipe-side triggers.
     'triggered_by': 'none',
     # Nearly all bots on these waterfalls are auto-rebooted between
     # runs for stability.
   },
@@ skipping 202 matching lines @@
     'build_config': 'Release',
     # Nearly all bots on these waterfalls are auto-rebooted between
     # runs for stability.
   },
 ]
 
 for slave in slaves:
   slave.update({
     '$recipe_engine': {'mode_flags': {'use_subprocess42': True}}
   })