Adding Trybots for Mac 10.11 to tryserver.chromium.mac for Findit use

masters/master.tryserver.chromium.mac/slaves.cfg

Index: masters/master.tryserver.chromium.mac/slaves.cfg
diff --git a/masters/master.tryserver.chromium.mac/slaves.cfg b/masters/master.tryserver.chromium.mac/slaves.cfg
index 39aedcd2d563595cf6214857197eddd4c9660205..5db70ace57dfbfd318ef394300b5bf0ba3089a50 100644
--- a/masters/master.tryserver.chromium.mac/slaves.cfg
+++ b/masters/master.tryserver.chromium.mac/slaves.cfg
@@ -54,6 +54,13 @@ def mac():
       'mac_chromium_variable_layout',
   ]
 
+  # Mac 10.11.
+  optional4_slaves = ['build417-m4']
+  optional4_builders = [
+      'mac_chromium_variable_10.11',
+      'mac_chromium_variable_10.11_layout',
+  ]
+
   out = []
   out.extend(
     {
@@ -134,6 +141,17 @@ def mac():
       'pool': 'mac_optional_10_10',
     } for slave in optional3_slaves
   )
+  out.extend(
+    {
+      'master': 'TryServerChromiumMac',
+      'builder': optional4_builders,
+      'hostname': slave,
+      'os': 'mac',
+      'version': '10.11',
+      'bits': '64',
+      'pool': 'mac_optional_10_11',
+    } for slave in optional4_slaves
+  )
 
   return out