Add swarming support for MB (and the GN bots) in the chromium recipes.

scripts/slave/recipes/chromium_trybot.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.
 
 from infra.libs.infra_types import freeze
 
 DEPS = [
   'bot_update',
   'chromium',
   'chromium_android',
@@ skipping 403 matching lines @@
     tests.append(api.chromium.steps.BlinkTest())
 
   compile_targets, tests_including_triggered = \
       api.chromium_tests.get_compile_targets_and_tests(
           bot_config['mastername'],
           bot_config['buildername'],
           master_dict,
           override_bot_type='builder_tester',
           override_tests=tests)
 
+  if api.m.chromium.c.project_generator.tool == 'mb':

[Paweł Hajdan Jr., 2015/06/10 10:27:19]

Why is the MB logic duplicated inline between chromium and chromium_trybot
recipes? Is there a way to share it? If not, what is preventing it?

[Dirk Pranke, 2015/06/10 16:11:40]

The way we build swarming_targets is a bit different between the two recipes, so
it's 
not clear to me that sharing the 5 lines of code makes things much clearer, but
I'll take a
stab at it so you can take a look.

+    swarming_targets = [
+      t.name for t in tests_including_triggered if t.uses_swarming
+    ]
+    api.m.chromium.run_mb(mastername, buildername,
+                          swarming_targets=swarming_targets)
+
   requires_compile, _, compile_targets = \
       api.chromium_tests.analyze(
           affected_files,
           all_compile_targets(api, tests + tests_including_triggered),
           compile_targets,
           'trybot_analyze_config.json')
 
   if not requires_compile:
     return
 
@@ skipping 555 matching lines @@
 
   yield (
     api.test('swarming_paths') +
     api.properties.tryserver(
       mastername='tryserver.chromium.linux',
       buildername='linux_chromium_rel_ng',
       path_config='swarming',
     ) +
     api.platform.name('linux')
   )