[Telemetry] Ensure run_benchmark sets the default values from AddCommandLineOptions.

tools/telemetry/telemetry/test.py

Index: tools/telemetry/telemetry/test.py
diff --git a/tools/telemetry/telemetry/test.py b/tools/telemetry/telemetry/test.py
index df74a2a5678d4b495980fe5ce27eb50e2bd3b507..3b5bcf39a7510ec356bf41e1108b93a9f8ed1a34 100644
--- a/tools/telemetry/telemetry/test.py
+++ b/tools/telemetry/telemetry/test.py
@@ -1,6 +1,7 @@
 # Copyright (c) 2013 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 optparse
 import os
 
 from telemetry.core import repeat_options
@@ -33,6 +34,12 @@ class Test(object):
     test = self.test()
     ps = self.CreatePageSet(options)
     expectations = self.CreateExpectations(ps)
+
+    # Ensure the test's default options are set if needed.
+    parser = optparse.OptionParser()
+    test.AddCommandLineOptions(parser)
+    options.MergeDefaultValues(parser.get_default_values())
+
     results = page_runner.Run(test, ps, expectations, options)
     results.PrintSummary()
     return len(results.failures) + len(results.errors)