Enable extra flags to make sure that C++ perf tests always output metrics

testing/scripts/run_gtest_perf_test.py

Index: testing/scripts/run_gtest_perf_test.py
diff --git a/testing/scripts/run_gtest_perf_test.py b/testing/scripts/run_gtest_perf_test.py
index 638929f3f5b87919c0ed4158ca562174e357fab3..06ade5f0443e3b18cf0f85b6e2882b09b36c3c55 100755
--- a/testing/scripts/run_gtest_perf_test.py
+++ b/testing/scripts/run_gtest_perf_test.py
@@ -88,6 +88,13 @@ def main():
       extra_flags = []
       if len(rest_args) > 1:
         extra_flags = rest_args[1:]
+
+      # These flags are to make sure that test output perf metrics in the log.
+      if not '--verbose' in extra_flags:
+        extra_flags.append('--verbose')
+      if not '--test-launcher-print-test-stdio=always' in extra_flags:
+        extra_flags.append('--test-launcher-print-test-stdio=always')
+
       if IsWindows():
         executable = '.\%s.exe' % executable
       else: