Make XR wrapper script report failures

Ensures that the wrapper script for the XR browser tests properly exits
with the browser tests' return code. Previously, it was doing nothing
with the returncode, causing the tests to appear to always exit with 0.

Bug: 954581
Change-Id: Iede65178478980a7e1770df9c4b20a38f2efa3b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1592616
Auto-Submit: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: Klaus Weidner <klausw@chromium.org>
Reviewed-by: Klaus Weidner <klausw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#656278}

chrome/browser/vr/test/run_xr_browser_tests.py

@@ -151,9 +151,9 @@ def main():
 
   test_executable = os.path.abspath(
       os.path.join(os.path.dirname(__file__), GetTestExecutable()))
-  subprocess.call(
+  sys.exit(subprocess.call(
       [test_executable, '--run-through-xr-wrapper-script'] +
-      tracing_args + rest_args)
+      tracing_args + rest_args))
 
 if __name__ == '__main__':
   main()