Add cloudtail start/stop in recipe_modules/goma

scripts/slave/recipe_modules/goma/example.py

 # Copyright 2016 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.
 
 DEPS = [
   'goma',
   'recipe_engine/platform',
   'recipe_engine/properties',
+  'recipe_engine/raw_io',
 ]
 
 def RunSteps(api):
   api.goma.ensure_goma()
   api.goma.start(env={})
   # build something using goma.
   api.goma.stop(
       ninja_log_outdir=api.properties.get('ninja_log_outdir'),
       ninja_log_compiler=api.properties.get('ninja_log_compiler'),
       ninja_log_command=api.properties.get('ninja_log_command'),
       ninja_log_exit_status=api.properties.get('ninja_log_exit_status'),
   )
 
 
 def GenTests(api):
   for platform in ('linux', 'win', 'mac'):
-    yield api.test(platform) + api.platform.name(platform)
+    step_data = api.step_data(
+        'start cloudtail',
+        stdout=api.raw_io.output('12345')
+    )
+    yield api.test(platform) + api.platform.name(platform) + step_data
 
     properties = {
         'build_data_dir': 'build_data_dir',
         'ninja_log_outdir': 'build_data_dir',
         'ninja_log_compiler': 'goma',
         'ninja_log_command': 'ninja -j 500',
         'ninja_log_exit_status': 0,
     }
 
     yield (api.test('%s_upload_logs' % platform) + api.platform.name(platform) +
-           api.properties.generic(**properties))
+           api.properties.generic(**properties) + step_data)