Returning correct failure code on swarmed perf test run.

testing/scripts/run_gtest_perf_test.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 """Runs an isolated non-Telemetry perf test .
 
 The main contract is that the caller passes the arguments:
 
   --isolated-script-test-output=[FILENAME]
@@ skipping 64 matching lines @@
   # Assume we want to set up the sandbox environment variables all the
   # time; doing so is harmless on non-Linux platforms and is needed
   # all the time on Linux.
   env[CHROME_SANDBOX_ENV] = CHROME_SANDBOX_PATH
   if args.xvfb and xvfb.should_start_xvfb(env):
     xvfb_proc, openbox_proc, xcompmgr_proc = xvfb.start_xvfb(env=env,
                                                              build_dir='.')
     assert xvfb_proc and openbox_proc and xcompmgr_proc, 'Failed to start xvfb'
 
   try:
-    valid = True
     rc = 0
     try:
       executable = rest_args[0]
       extra_flags = []
       if len(rest_args) > 1:
         extra_flags = rest_args[1:]
       if IsWindows():
         executable = '.\%s.exe' % executable
       else:
         executable = './%s' % executable
       with common.temporary_file() as tempfile_path:
-        valid = (common.run_command_with_output([executable] + extra_flags,
-            env=env, stdoutfile=tempfile_path) == 0)
+        rc = common.run_command_with_output([executable] + extra_flags,
+            env=env, stdoutfile=tempfile_path)
 
         # Now get the correct json format from the stdout to write to the
         # perf results file
         results_processor = (
             generate_legacy_perf_dashboard_json.LegacyResultsProcessor())
         charts = results_processor.GenerateJsonResults(tempfile_path)
         # Write the returned encoded json to a the charts output file
         with open(args.isolated_script_test_chartjson_output, 'w') as f:
           f.write(charts)
     except Exception:
       traceback.print_exc()
-      valid = False
+      rc = 1
 
+    valid = (rc == 0)
     failures = [] if valid else ['(entire test suite)']
     with open(args.isolated_script_test_output, 'w') as fp:
       json.dump({
           'valid': valid,
           'failures': failures,
       }, fp)
 
     return rc
 
   finally:
@@ skipping 11 matching lines @@
 if __name__ == '__main__':
   # Conform minimally to the protocol defined by ScriptTest.
   if 'compile_targets' in sys.argv:
     funcs = {
       'run': None,
       'compile_targets': main_compile_targets,
     }
     sys.exit(common.run_script(sys.argv[1:], funcs))
   sys.exit(main())