* Output of `node_modules/.bin/electron --version`: v5.0.0-nightly.20190107
* Operating System (Platform and Version): macOS Mojave 10.14.2 (18C54)
* Output of `node_modules/.bin/electron --version` on last known working Electron version (if applicable): never

**Expected Behavior**
Using navigator.mediaDevices.getDisplayMedia({ video: true }), a native screen picker should appear.

**Actual behavior**
The following error is thrown: NotAllowedError: Permission denied

**Screenshots**
Expected dialog
![image](https://user-images.githubusercontent.com/1120050/51625551-71736500-1f0b-11e9-9a95-1406cad95046.png)
atom/browser/atom_browser_client.h
}
namespace atom {
class AtomResourceDispatcherHostDelegate;
class NotificationPresenter;
class PlatformNotificationService;
class AtomBrowserClient : public content::ContentBrowserClient,
                          public content::RenderProcessHostObserver {
 public:
  static AtomBrowserClient* Get();
  static void SetApplicationLocale(const std::string& locale);
  AtomBrowserClient();
  ~AtomBrowserClient() override;
  using Delegate = content::ContentBrowserClient;
  void set_delegate(Delegate* delegate) { delegate_ = delegate; }
  
  content::WebContents* GetWebContentsFromProcessID(int process_id);
  
  static void SuppressRendererProcessRestartForOnce();
  NotificationPresenter* GetNotificationPresenter();
  void WebNotificationAllowed(int render_process_id,
                              const base::Callback<void(bool, bool)>& callback);
  
  std::vector<std::unique_ptr<content::NavigationThrottle>>
  CreateThrottlesForNavigation(content::NavigationHandle* handle) override;
  
  std::string GetApplicationLocale() override;
  
  bool ShouldEnableStrictSiteIsolation() override;