- Electron version: v0.36.9
- Operating system: Windows 10/OS X

In #779 a `disposition` was added to the `new-window` event in [webContents](https://github.com/atom/electron/blob/master/docs/api/web-contents.md#event-new-window) but it always seems to be set to `new-window` when clicking on target="_blank" links in our web app wrapper: https://github.com/irccloud/irccloud-desktop/blob/v0.1.3/app/main.js#L109

If I Ctrl (Win) or Cmd (OS X) or middle click on links, I would expect to see a `background-tab` disposition, as in Chrome that will open links in a background tab, while keeping focus on the current tab. I'd like to catch this behaviour to set `activate` to false in `shell.openExternal`.

Is this possible?

atom/browser/api/atom_api_web_contents.cc
if (type_ == REMOTE)
    return;
  managed_web_contents()->CloseDevTools();
}
bool WebContents::IsDevToolsOpened() {
  if (type_ == REMOTE)
    return false;
  return managed_web_contents()->IsDevToolsViewShowing();
}
bool WebContents::IsDevToolsFocused() {
  if (type_ == REMOTE)
    return false;
  return managed_web_contents()->GetView()->IsDevToolsViewFocused();
}
void WebContents::EnableDeviceEmulation(
    const blink::WebDeviceEmulationParams& params) {
  if (type_ == REMOTE)
    return;
  Send(new ViewMsg_EnableDeviceEmulation(routing_id(), params));
}
void WebContents::DisableDeviceEmulation() {
  if (type_ == REMOTE)
    return;
  Send(new ViewMsg_DisableDeviceEmulation(routing_id()));
}
void WebContents::ToggleDevTools() {