Updating benchmark script to only write chartjson when flag present.

testing/scripts/run_telemetry_benchmark_as_googletest.py

Index: testing/scripts/run_telemetry_benchmark_as_googletest.py
diff --git a/testing/scripts/run_telemetry_benchmark_as_googletest.py b/testing/scripts/run_telemetry_benchmark_as_googletest.py
index dd8d23b69bd04a29ded9edbc6bbfbe53bea1b14f..674c4c9e9433beac1c6bfc372ff7c0d6511d0f23 100755
--- a/testing/scripts/run_telemetry_benchmark_as_googletest.py
+++ b/testing/scripts/run_telemetry_benchmark_as_googletest.py
@@ -44,9 +44,18 @@ def main():
   parser.add_argument(
       '--isolated-script-test-output', type=argparse.FileType('w'),
       required=True)
-  parser.add_argument(
-    '--isolated-script-test-chartjson-output', type=argparse.FileType('w'),
-    required=False)
+  # Only create the chartjson directory if this test is producing chartjson
+  # results.  Otherwise, remove from the argument list.
+  writing_chartjson_results = '--output-format=chartjson' in sys.argv
+  if writing_chartjson_results:
+    parser.add_argument(
+      '--isolated-script-test-chartjson-output', type=argparse.FileType('w'),
+      required=False)
+  else:
+    for arg in sys.argv:
+      if 'isolated-script-test-chartjson-output' in arg:
+        sys.argv.remove(arg)
+        break

[Ken Russell (switch to Gerrit), 2016/09/22 20:31:48]

Instead of this somewhat contorted code, could you just change the
parser.add_argument call to use type=str, and open the file yourself lazily
below? I think that would be more maintainable.

[eyaich1, 2016/09/23 13:52:38]

Done.

   parser.add_argument('--xvfb', help='Start xvfb.', action='store_true')
   args, rest_args = parser.parse_known_args()
   xvfb_proc = None
@@ -65,8 +74,8 @@ def main():
     tempfile_dir = tempfile.mkdtemp('telemetry')
     valid = True
     failures = []
-    chartjson = (args.isolated_script_test_chartjson_output is not None and
-      '--output-format=chartjson' in rest_args)
+    chartjson = (writing_chartjson_results
+      and args.isolated_script_test_chartjson_output is not None)
     chartresults = None
     try:
       rc = common.run_command([sys.executable] + rest_args + [