Ignore Chromium-specific flags on video_quality_loopback_test.

TBR=phoglund@webrtc.org

Bug: chromium:755660
Change-Id: I71409a569995708bc4c54b9bbcb2a119feed4be9
Reviewed-on: https://webrtc-review.googlesource.com/46524
Commit-Queue: Edward Lemur <ehmaldonado@webrtc.org>
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Reviewed-by: Edward Lemur <ehmaldonado@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21827}

examples/androidtests/video_quality_loopback_test.py

@@ -89,7 +89,19 @@ def _ParseArgs():
   parser.add_argument('--chartjson-result-file',
       help='Where to store perf results in chartjson format.', default=None)
 
-  args = parser.parse_args()
+  args, unknown_args = parser.parse_known_args()
+
+  # Ignore Chromium-specific flags
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--isolated-script-test-output',
+                      type=str, default=None)
+  parser.add_argument('--isolated-script-test-perf-output',
+                      type=str, default=None)
+  parser.add_argument('--test-launcher-summary-output',
+                      type=str, default=None)
+
+  parser.parse_args(unknown_args)
+
   return args