Pass unparsed arguments through to the weblayer instrumentation test.

Bug: 1058963
Change-Id: If7d10216e236282357f88e3cc49a5a2c5b3200a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2150395Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Erik Staab <estaab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759404}

weblayer/browser/android/javatests/weblayer_instrumentation_test_versions.py

@@ -50,7 +50,7 @@ def main():
       '--implementation-outdir',
       required=True,
       help='Build output directory for WebLayer implementation.')
-  args = parser.parse_args()
+  args, remaining_args = parser.parse_known_args()
 
   logging.basicConfig(level=logging.INFO)
 
@@ -82,7 +82,7 @@ def main():
       '--additional-apk',
       os.path.join(args.tests_outdir, 'apks/ChromiumNetTestSupport.apk')]
 
-  cmd = [executable_path] + executable_args
+  cmd = [executable_path] + executable_args + remaining_args
   cmd = [sys.executable] + cmd
   logging.info(' '.join(cmd))
   return subprocess.call(cmd)