* Electron Version 6.0.0-beta.12
* Operating System Windows 10 64 bit

Expected Behavior
webContents.print() should send print a job to the specified printer

Actual behavior
Nothing happens. Callback gets called much latter, for example on program exit.

To Reproduce
let print_options = { 
    silent: true,
    printBackground: true,
    deviceName: barcode_device_name 
}
print_window.webContents.print(print_options, (data) => {
    console.log(`print result: ${data}`)
})

Related to #17260
shell/browser/api/atom_api_web_contents.cc
v8::Isolate* isolate,
    content::WebContents* web_contents) {
  auto existing = From(isolate, web_contents);
  if (!existing.IsEmpty())
    return existing;
  else
    return mate::CreateHandle(isolate, new WebContents(isolate, web_contents));
}
}  
}  
namespace {
using electron::api::WebContents;
void Initialize(v8::Local<v8::Object> exports,
                v8::Local<v8::Value> unused,
                v8::Local<v8::Context> context,
                void* priv) {
  v8::Isolate* isolate = context->GetIsolate();
  mate::Dictionary dict(isolate, exports);
  dict.Set("WebContents", WebContents::GetConstructor(isolate)
                              ->GetFunction(context)
                              .ToLocalChecked());
  dict.SetMethod("create", &WebContents::Create);
  dict.SetMethod("fromId", &mate::TrackableObject<WebContents>::FromWeakMapID);
  dict.SetMethod("getAllWebContents",
                 &mate::TrackableObject<WebContents>::GetAll);
}
}  
NODE_LINKED_MODULE_CONTEXT_AWARE(atom_browser_web_contents, Initialize)