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

scripts/slave/recipe_modules/chromium_tests/steps.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.
 
 import re
 import string
 
 
 class Test(object):
   """
@@ skipping 288 matching lines @@
       kwargs['tool'] = self._android_tool
     else:
       kwargs['xvfb'] = True
       kwargs['test_type'] = self.name
       kwargs['annotate'] = 'gtest'
       kwargs['test_launcher_summary_output'] = gtest_results_file
       kwargs.update(self._runtest_kwargs)
 
     try:
       if is_android:
-        api.chromium_android.run_test_suite(self.target_name, **kwargs)
+        with api.chromium_android.logcat(self.name):
+          api.chromium_android.run_test_suite(self.target_name, **kwargs)
       elif self._use_isolate:
         api.isolate.runtest(self.target_name, self._revision,
                             self._webkit_revision, **kwargs)
       else:
         api.chromium.runtest(self.target_name, revision=self._revision,
                              webkit_revision=self._webkit_revision, **kwargs)
     finally:
       step_result = api.step.active_result
       self._test_runs[suffix] = step_result
 
@@ skipping 1267 matching lines @@
     self._test_apk = test_apk or suite_defaults.get('test_apk')
     self._tool = tool
     self._verbose = verbose
 
   #override
   def run_tests(self, api, suffix, json_results_file):
     mock_test_results = {
       'per_iteration_data': [{'TestA': [{'status': 'SUCCESS'}]},
                              {'TestB': [{'status': 'FAILURE'}]}]
     }
-    api.chromium_android.run_instrumentation_suite(
-        self.name,
-        test_apk=api.chromium_android.apk_path(self._test_apk),
-        apk_under_test=api.chromium_android.apk_path(self._apk_under_test),
-        suffix=suffix,
-        isolate_file_path=self.isolate_file_path,
-        flakiness_dashboard=self._flakiness_dashboard,
-        annotation=self._annotation, except_annotation=self._except_annotation,
-        screenshot=self._screenshot, verbose=self._verbose, tool=self._tool,
-        host_driven_root=self._host_driven_root,
-        json_results_file=json_results_file,
-        step_test_data=lambda: api.json.test_api.output(mock_test_results))
+    with api.chromium_android.logcat(self.name):
+      api.chromium_android.run_instrumentation_suite(
+          self.name,
+          test_apk=api.chromium_android.apk_path(self._test_apk),
+          apk_under_test=api.chromium_android.apk_path(self._apk_under_test),
+          suffix=suffix,
+          isolate_file_path=self.isolate_file_path,
+          flakiness_dashboard=self._flakiness_dashboard,
+          annotation=self._annotation,
+          except_annotation=self._except_annotation,
+          screenshot=self._screenshot, verbose=self._verbose, tool=self._tool,
+          host_driven_root=self._host_driven_root,
+          json_results_file=json_results_file,
+          step_test_data=lambda: api.json.test_api.output(mock_test_results))
 
 
 class BlinkTest(Test):
   # TODO(dpranke): This should be converted to a PythonBasedTest, although it
   # will need custom behavior because we archive the results as well.
   def __init__(self, extra_args=None):
     super(BlinkTest, self).__init__()
     self._extra_args = extra_args
 
   name = 'webkit_tests'
@@ skipping 170 matching lines @@
   def run(self, api, suffix):
     api.chromium_android.coverage_report(upload=False)
     api.chromium_android.get_changed_lines_for_revision()
     api.chromium_android.incremental_coverage_report()
 
 
 GOMA_TESTS = [
   GTestTest('base_unittests'),
   GTestTest('content_unittests'),
 ]