Fix swarming tests not running in parallel

tools-webrtc/gtest-parallel-wrapper.py

 #!/usr/bin/env python
 
 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
@@ skipping 41 matching lines @@
 
 
 def main():
   # Ignore '--'. Options unprocessed by this script will be passed to the test
   # as arguments.
   if '--' in sys.argv:
     del sys.argv[sys.argv.index('--')]
 
   parser = argparse.ArgumentParser()
   parser.add_argument('--isolated-script-test-output', type=str, default=None)
+
+  # TODO(ehmaldonado): Implement this flag instead of just "eating" it.
+  parser.add_argument('--isolated-script-test-chartjson-output', type=str,
+                      default=None)
+
   parser.add_argument('--output_dir', type=str, default=None)
   parser.add_argument('--timeout', type=int, default=None)
 
   # GTEST_SHARD_INDEX and GTEST_TOTAL_SHARDS must be removed from the
   # environment. Otherwise it will be picked up by the binary, causing a bug
   # where only tests in the first shard are executed.
   test_env = os.environ.copy()
   gtest_shard_index = test_env.pop('GTEST_SHARD_INDEX', '0')
   gtest_total_shards = test_env.pop('GTEST_TOTAL_SHARDS', '1')
 
@@ skipping 51 matching lines @@
     logs = [os.path.join(logs_dir, log) for log in os.listdir(logs_dir)]
     log_file = os.path.join(options.output_dir, '%s-tests.log' % test_status)
     cat_files(logs, log_file)
     os.rmdir(logs_dir)
 
   return exit_code
 
 
 if __name__ == '__main__':
   sys.exit(main())