Disable swarming for the new 10.9 testers, since there's no swarming bots yet.

scripts/slave/recipe_modules/chromium/chromium_mac.py

 # Copyright 2014 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.
 
 from . import steps
 
 SPEC = {
   'settings': {
     'build_gs_bucket': 'chromium-mac-archive',
   },
@@ skipping 41 matching lines @@
         'TARGET_BITS': 32,
       },
       'test_generators': [
         steps.generate_gtest,
         steps.generate_script,
       ],
       'bot_type': 'tester',
       'parent_buildername': 'Mac Builder',
       'testing': {
         'platform': 'mac',
+      },
+      'enable_swarming': True,
+      'swarming_dimensions': {
         'os': 'Mac-10.8',
       },
-      'enable_swarming': True,
     },
     'Mac10.9 Tests': {
       'recipe_config': 'chromium',
       'chromium_config_kwargs': {
         'BUILD_CONFIG': 'Release',
         'TARGET_BITS': 32,
       },
       'test_generators': [
         steps.generate_gtest,
         steps.generate_script,
       ],
       'bot_type': 'tester',
       'parent_buildername': 'Mac Builder',
       'testing': {
         'platform': 'mac',
+      },
+      'enable_swarming': False,
+      'swarming_dimensions': {
         'os': 'Mac-10.9',
       },
-      'enable_swarming': True,
     },
     'Mac Builder (dbg)': {
       'recipe_config': 'chromium',
       'chromium_config_kwargs': {
         'BUILD_CONFIG': 'Debug',
         'TARGET_BITS': 32,
       },
       'bot_type': 'builder',
       'compile_targets': [
         'chromium_builder_tests',
@@ skipping 12 matching lines @@
       },
       'test_generators': [
         steps.generate_gtest,
         steps.generate_script,
       ],
       'bot_type': 'tester',
       'parent_buildername': 'Mac Builder (dbg)',
       'testing': {
         'platform': 'mac',
       },
-      'enable_swarming': True,
+      'enable_swarming': False,
       'swarming_dimensions': {
         'os': 'Mac-10.9',
       },
     },
     'iOS Device': {
       'recipe_config': 'chromium_ios_device',
       'chromium_config_kwargs': {
         'BUILD_CONFIG': 'Release',
         'TARGET_PLATFORM': 'ios',
         'TARGET_BITS': 32,
@@ skipping 29 matching lines @@
       },
       'gclient_config_kwargs': {
         'GIT_MODE': True,
       },
       'testing': {
         'platform': 'mac',
       }
     },
   },
 }