Just saw this when perfbot sheriffing:
https://ci.chromium.org/buildbot/chromium.perf/Android%20Nexus5X%20WebView%20Perf/1997
https://logs.chromium.org/v/?s=chrome%2Fbb%2Fchromium.perf%2FAndroid_Nexus5X_WebView_Perf%2F1997%2F%2B%2Frecipes%2Fsteps%2Fblink_perf.svg_on_Android_device_Nexus_5X%2F0%2Fstdout
Traceback (most recent call last):
  File "../../third_party/catapult/devil/devil/android/tools/system_app.py", line 218, in <module>
    sys.exit(main(sys.argv[1:]))
  File "../../third_party/catapult/devil/devil/android/tools/system_app.py", line 208, in main
    devices = script_common.GetDevices(args.devices, args.blacklist_file)
  File "/b/swarming/w/ir/third_party/catapult/devil/devil/android/tools/script_common.py", line 47, in GetDevices
    raise device_errors.NoDevicesError()
devil.android.device_errors.NoDevicesError: No devices attached.

This should be purple--it shows up as red so that I assume it doesn't alert labs, and it also shows up as a test (not infra) failure in sheriff-o-matic.

Not sure what the right component for this is?