- 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.h
#ifndef ATOM_BROWSER_ATOM_BROWSER_CLIENT_H_
#define ATOM_BROWSER_ATOM_BROWSER_CLIENT_H_
#include <map>
#include <string>
#include <vector>
#include "brightray/browser/browser_client.h"
#include "content/public/browser/render_process_host_observer.h"
namespace content {
class QuotaPermissionContext;
class ClientCertificateDelegate;
}
namespace net {
class SSLCertRequestInfo;
}
namespace atom {
class AtomResourceDispatcherHostDelegate;
class AtomBrowserClient : public brightray::BrowserClient,
                          public content::RenderProcessHostObserver {
 public:
  AtomBrowserClient();
  virtual ~AtomBrowserClient();
  using Delegate = content::ContentBrowserClient;
  void set_delegate(Delegate* delegate) { delegate_ = delegate; }