[Android] Add context manager to record logcat during step(s).

scripts/slave/recipe_modules/chromium_android/example.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 recipe_engine.types import freeze
 
 DEPS = [
     'adb',
     'chromium',
     'chromium_android',
@@ skipping 163 matching lines @@
       official_build=True,
       host_driven_root=api.path['checkout'].join('chrome', 'test'))
   api.chromium_android.run_test_suite(
       'unittests',
       isolate_file_path=api.path['checkout'].join('some_file.isolate'),
       gtest_filter='WebRtc*',
       tool='asan')
   if not failure:
       api.chromium_android.run_bisect_script(extra_src='test.py',
                                              path_to_config='test.py')
-  api.chromium_android.logcat_dump()
-  api.chromium_android.stack_tool_steps()
+
+  logcat_file = api.chromium.output_dir.join('full_logcat')
+  api.chromium_android.logcat_dump(output_logcat_file=logcat_file)

[luqui, 2015/11/23 22:59:40]

Heck as long as you're here you might as well use the context manager, right?

[mikecase (-- gone --), 2015/11/24 20:50:59]

Added an example of using the logcat context manager above for the test runs.

+  api.chromium_android.stack_tool_steps(logcat_file=logcat_file)
   if config.get('coverage', False):
     api.chromium_android.coverage_report()
 
   if failure:
     raise failure
 
 def GenTests(api):
   def properties_for(buildername):
     return api.properties.generic(
         buildername=buildername,
@@ skipping 31 matching lines @@
 
   yield (api.test('gerrit_refs') +
       api.properties.generic(
         buildername='gerrit_try_builder',
         slavename='testslave',
         repo_name='src/repo',
         patch_url='https://the.patch.url/the.patch',
         repo_url='svn://svn.chromium.org/chrome/trunk/src',
         revision='4f4b02f6b7fa20a3a25682c457bbc8ad589c8a00',
         internal=True, **({'event.patchSet.ref':'refs/changes/50/176150/1'})))