Replace 10.7 testers with 10.9 in master.chromium.mac

masters/master.chromium.mac/slaves.cfg

 # -*- python -*-
 # ex: set syntax=python:
 
 # 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.
 
 # See master.experimental/slaves.cfg for documentation.
 
 
 slaves = [
 ################################################################################
 # Mac
 ################################################################################
   {
     'master': 'ChromiumMac',
     'hostname': 'vm633-m1',
     'builder': 'Mac Builder',
     'os': 'mac',
     'version': '10.8',
     'bits': '64',
   },
   {
     'master': 'ChromiumMac',
     'hostname': 'vm600-m1',
-    'builder': 'Mac10.7 Tests (1)',
+    'builder': 'Mac10.9 Tests',
     'os': 'mac',
-    'version': '10.7',
+    'version': '10.9',
     'bits': '64',
   },
   {
     'master': 'ChromiumMac',
     'hostname': 'vm9-a1',
-    'builder': 'Mac10.6 Tests (1)',
+    'builder': 'Mac10.6 Tests',
     'os': 'mac',
     'version': '10.6',
     'bits': '64',
   },
   {
     'master': 'ChromiumMac',
     'hostname': 'vm645-m1',
     'builder': 'Mac Builder (dbg)',
     'os': 'mac',
     'version': '10.8',
     'bits': '64',
   },
   {
     'master': 'ChromiumMac',
     'hostname': 'vm11-a1',
-    'builder': 'Mac 10.7 Tests (dbg)(1)',
+    'builder': 'Mac10.9 Tests (dbg)',
     'os': 'mac',
-    'version': '10.7',
+    'version': '10.9',
     'bits': '64',
   },
   {
     'master': 'ChromiumMac',
     'hostname': 'vm7-a1',
-    'builder': 'Mac 10.6 Tests (dbg)(1)',
+    'builder': 'Mac10.8 Tests',
     'os': 'mac',
-    'version': '10.6',
+    'version': '10.8',
     'bits': '64',
   },
   {
     'master': 'ChromiumMac',
     'hostname': 'mini43-a1',
     'builder': ['iOS Simulator (dbg)', 'iOS Device', 'iOS Device (ninja)',],
     'os': 'mac',
     'version': '10.7',
   },
 ]