chromium_tests: automatically set up test genrators

scripts/slave/recipe_modules/chromium_tests/api.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 collections
 import contextlib
 import copy
 import itertools
 import json
 
@@ skipping 216 matching lines @@
       buildername, mastername, enable_swarming, swarming_dimensions,
       scripts_compile_targets, generators, bot_update_step):
     tests = builder_dict.get('tests', ())
     # TODO(phajdan.jr): Switch everything to scripts generators and simplify.
     for generator in generators:
       tests = (
           tuple(generator(api, self, mastername, buildername, test_spec,
                           bot_update_step, enable_swarming=enable_swarming,
                           swarming_dimensions=swarming_dimensions,
                           scripts_compile_targets=scripts_compile_targets)) +
-          tests)
+          tuple(tests))
     return tests
 
   def read_test_spec(self, api, test_spec_file):
     test_spec_path = api.path['checkout'].join('testing', 'buildbot',
                                                test_spec_file)
     test_spec_result = api.json.read(
         'read test spec (%s)' % api.path.basename(test_spec_path),
         test_spec_path,
         step_test_data=lambda: api.json.test_api.output({}))
     test_spec_result.presentation.step_text = 'path: %s' % test_spec_path
@@ skipping 768 matching lines @@
     targets in |compile_targets|."""
     result = []
     for test in tests:
       test_compile_targets = test.compile_targets(api)
       # Always return tests that don't require compile. Otherwise we'd never
       # run them.
       if ((set(compile_targets) & set(test_compile_targets)) or
           not test_compile_targets):
         result.append(test)
     return result