swarming: always append task's OS dimension to step name

scripts/slave/recipes/v8.py

 # Copyright 2013 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 = [
   'archive',
   'chromium',
   'depot_tools/gclient',
   'recipe_engine/json',
   'recipe_engine/path',
@@ skipping 183 matching lines @@
     ) +
     api.override_step_data('Check', api.v8.one_failure())
   )
 
   yield (
     api.v8.test(
         'client.v8',
         'V8 Fuzzer',
         'fuzz_archive',
     ) +
-    api.override_step_data('Fuzz', retcode=1)
+    api.override_step_data('Fuzz on Ubuntu-12.04', retcode=1)
   )
 
   # Bisect over range a1, a2, a3. Assume a2 is the culprit. Steps:
   # Bisect a0 -> no failures.
   # Bisect a2 -> failures.
   # Bisect a1 -> no failures.
   # Report culprit a2.
   yield (
     api.v8.test(
         'client.v8',
@@ skipping 117 matching lines @@
     api.v8.fail('Mjsunit') +
     api.override_step_data(
         'Bisect.Fetch changes', api.v8.example_one_buildbot_change()) +
     api.override_step_data(
         'Bisect.Get change range',
         api.v8.example_bisection_range_one_change(),
     ) +
 
     api.time.step(120)
   )