[Telemetry] Makes serially_executed_browser_test_case.LoadAllTestsInModule return nothing if not ex…

telemetry/telemetry/testing/serially_executed_browser_test_case.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.
 
 import inspect
 import re
 import unittest
 
 from py_utils import cloud_storage
 from telemetry.internal.browser import browser_finder
@@ skipping 124 matching lines @@
   #################################################################
 
   Args:
     module: the module which contains test cases classes.
 
   Returns:
     an instance of unittest.TestSuite, which contains all the tests & generated
     test cases to be run.
   """
   suite = unittest.TestSuite()
+  finder_options = options_for_unittests.GetCopy()
+  if not hasattr(finder_options, 'browser_test_runner_running'):
+    return suite
   for _, obj in inspect.getmembers(module):
     if (inspect.isclass(obj) and
         issubclass(obj, SeriallyExecutedBrowserTestCase)):
       for test in GenerateTestCases(
-          test_class=obj, finder_options=options_for_unittests.GetCopy()):
+          test_class=obj, finder_options=finder_options):
         suite.addTest(test)
   return suite
 
 
 def _GenerateTestMethod(based_method, args):
   return lambda self: based_method(self, *args)
 
 
 _TEST_GENERATOR_PREFIX = 'GenerateTestCases_'
 _INVALID_TEST_NAME_RE = re.compile(r'[^a-zA-Z0-9_]')
@@ skipping 20 matching lines @@
       assert hasattr(test_class, based_method_name), (
           '%s is specified but based method %s does not exist' %
           (name, based_method_name))
       based_method = getattr(test_class, based_method_name)
       for generated_test_name, args in method(finder_options):
         _ValidateTestMethodname(generated_test_name)
         setattr(test_class, generated_test_name, _GenerateTestMethod(
             based_method, args))
         test_cases.append(test_class(generated_test_name))
   return test_cases