- 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/atom_browser_client.cc
AtomBrowserClient::CreateSpeechRecognitionManagerDelegate() {
  return new AtomSpeechRecognitionManagerDelegate;
}
content::AccessTokenStore* AtomBrowserClient::CreateAccessTokenStore() {
  return new AtomAccessTokenStore;
}
void AtomBrowserClient::OverrideWebkitPrefs(
    content::RenderViewHost* host, content::WebPreferences* prefs) {
  prefs->javascript_enabled = true;
  prefs->web_security_enabled = true;
  prefs->javascript_can_open_windows_automatically = true;
  prefs->plugins_enabled = true;
  prefs->dom_paste_enabled = true;
  prefs->allow_scripts_to_close_windows = true;
  prefs->javascript_can_access_clipboard = true;
  prefs->local_storage_enabled = true;
  prefs->databases_enabled = true;
  prefs->application_cache_enabled = true;
  prefs->allow_universal_access_from_file_urls = true;
  prefs->allow_file_access_from_file_urls = true;
  prefs->experimental_webgl_enabled = true;
  prefs->allow_displaying_insecure_content = false;
  prefs->allow_running_insecure_content = false;
  
  auto web_contents = content::WebContents::FromRenderViewHost(host);
  WebContentsPreferences::OverrideWebkitPrefs(web_contents, prefs);
}
std::string AtomBrowserClient::GetApplicationLocale() {