Convert most Chromium presubmit files to use new multiple-tryserver-compatible protocol

native_client_sdk/PRESUBMIT.py

 # 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.
 
 """Top-level presubmit script for isolate.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
@@ skipping 20 matching lines @@
 
 
 def CheckChangeOnUpload(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def CheckChangeOnCommit(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
-def GetPreferredTrySlaves(project, change):
-  return [
-    'linux_nacl_sdk',
-    'linux_nacl_sdk_build',
-    'win_nacl_sdk',
-    'win_nacl_sdk_build',
-    'mac_nacl_sdk',
-    'mac_nacl_sdk_build'
-  ]
+def GetPreferredTryMasters(project, change):
+  return {
+    'tryserver.chromium': {
+      'linux_nacl_sdk': set(['defaulttests']),
+      'linux_nacl_sdk_build': set(['defaulttests']),
+      'win_nacl_sdk': set(['defaulttests']),
+      'win_nacl_sdk_build': set(['defaulttests']),
+      'mac_nacl_sdk': set(['defaulttests']),
+      'mac_nacl_sdk_build': set(['defaulttests']),
+    }
+  }