Add Mac10.12 builders to list of supported Blink builders.

third_party/WebKit/Tools/Scripts/webkitpy/common/config/builders.py

 # Copyright (c) 2016, Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 49 matching lines @@
         "specifiers": ['Mac10.11', 'Release']
     },
     "WebKit Mac10.11 (dbg)": {
         "port_name": "mac-mac10.11",
         "specifiers": ['Mac10.11', 'Debug']
     },
     "WebKit Mac10.11 (retina)": {
         "port_name": "mac-retina",
         "specifiers": ['Retina', 'Release']
     },
+    "WebKit Mac10.12": {
+        "port_name": "mac-mac10.12",
+        "specifiers": ['Mac10.12', 'Release']
+    },
     "WebKit Android (Nexus4)": {
         "port_name": "android",
         "specifiers": ['Android', 'Release']
     },
     "linux_trusty_blink_rel": {
         "port_name": "linux-trusty",
         "specifiers": ['Trusty', 'Release'],
         "is_try_builder": True,
     },
     "mac10.9_blink_rel": {
         "port_name": "mac-mac10.9",
         "specifiers": ['Mac10.9', 'Release'],
         "is_try_builder": True,
     },
     "mac10.10_blink_rel": {
         "port_name": "mac-mac10.10",
         "specifiers": ['Mac10.10', 'Release'],
         "is_try_builder": True,
     },
     "mac10.11_blink_rel": {
         "port_name": "mac-mac10.11",
         "specifiers": ['Mac10.11', 'Release'],
         "is_try_builder": True,
     },
     "mac10.11_retina_blink_rel": {
         "port_name": "mac-retina",
         "specifiers": ['Retina', 'Release'],
         "is_try_builder": True,
     },
+    "mac10.12_blink_rel": {
+        "port_name": "mac-mac10.12",
+        "specifiers": ['Mac10.12', 'Release'],
+        "is_try_builder": True,
+    },
     "win7_blink_rel": {
         "port_name": "win-win7",
         "specifiers": ['Win7', 'Release'],
         "is_try_builder": True,
     },
     "win10_blink_rel": {
         "port_name": "win-win10",
         "specifiers": ['Win10', 'Release'],
         "is_try_builder": True,
     },
     "android_blink_rel": {
         "port_name": "android",
         "specifiers": ['Android', 'Release'],
         "is_try_builder": True,
     },
 }