Fix writing GPU test runner arguments to results file

content/test/gpu/run_gpu_integration_test.py

 #!/usr/bin/env python
 # 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 argparse
 import json
+import os
 import sys
 
 from gpu_tests import path_util
 import gpu_project_config
 
 path_util.SetupTelemetryPaths()
 
 from telemetry.testing import browser_test_runner
 
 def PostprocessJSON(file_name, run_test_args):
-  def TrimPrefix(s):
-    return s[1 + s.rfind('.'):]
-  with open(file_name) as f:
-    test_result = json.load(f)
-  test_result['successes'] = map(TrimPrefix, test_result['successes'])
-  test_result['failures'] = map(TrimPrefix, test_result['failures'])
-  test_result['run_test_args'] = run_test_args
-  with open(file_name, 'w') as f:
-    json.dump(test_result, f)
+  # The file is not necessarily written depending on the arguments - only
+  # postprocess it in case it is.
+  if os.path.isfile(file_name):
+    with open(file_name) as f:
+      test_result = json.load(f)
+    test_result['run_test_args'] = run_test_args
+    with open(file_name, 'w') as f:
+      json.dump(test_result, f, indent=2)
 
 def main():
   rest_args = sys.argv[1:]
+  parser = argparse.ArgumentParser(description='Extra argument parser',
+                                   add_help=False)
+
+  parser.add_argument(
+    '--write-run-test-arguments',
+    action='store_true',
+    help=('Write the test script arguments to the results file.'))
+  option, rest_args_filtered = parser.parse_known_args(rest_args)
+
   retval = browser_test_runner.Run(
-      gpu_project_config.CONFIG, rest_args)
-  # Postprocess the outputted JSON to trim all of the prefixes from
-  # the test names, to keep them as similar to the old form as
-  # possible -- and keep them from getting crazily long.
-  parser = argparse.ArgumentParser(description='Temporary argument parser')
+      gpu_project_config.CONFIG, rest_args_filtered)
+
+  # We're not relying on argparse to print the help in the normal way, because
+  # we need the help output from both the argument parser here and the argument
+  # parser in browser_test_runner.
+  if '--help' in rest_args:
+    parser.print_help()
+    return retval
+
+  # This duplicates an argument of browser_test_runner.
   parser.add_argument(
-    '--write-abbreviated-json-results-to', metavar='FILENAME',
+    '--write-full-results-to', metavar='FILENAME',
     action='store',
-    help=('Full path for json results'))
+    help=('If specified, writes the full results to that path.'))
+
   option, _ = parser.parse_known_args(rest_args)
-  if option.write_abbreviated_json_results_to:
-    PostprocessJSON(option.write_abbreviated_json_results_to, rest_args)
+
+  # Postprocess the outputted JSON to add test arguments.
+  if option.write_run_test_arguments and option.write_full_results_to:
+    PostprocessJSON(option.write_full_results_to, rest_args)
   return retval
 
 if __name__ == '__main__':
   sys.exit(main())