Not sure this will affect Android part(both extension are exposed same namespace `xwalk.experimental.system`). To be safe, please add this under
```
#if !defined(OS_ANDROID)
  server->RegisterExtension(scoped_ptr<XWalkExtension>(
    new sysapps::DeviceCapabilitiesExtension(runtime_registry_.get()))); 
#endif
```

ping @cmarcelo and @tmpsantos @yongsheng to confirm.