* 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.cc
const scoped_refptr<network::ResourceRequestBody>& body,
    bool user_gesture,
    bool opener_suppressed,
    bool* no_javascript_access) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  int opener_render_process_id = opener->GetProcess()->GetID();
  if (IsRendererSandboxed(opener_render_process_id)) {
    *no_javascript_access = false;
    return true;
  }
  if (RendererUsesNativeWindowOpen(opener_render_process_id)) {
    if (RendererDisablesPopups(opener_render_process_id)) {
      
      
      return false;
    } else {
      *no_javascript_access = false;
      return true;
    }
  }
  if (delegate_) {
    return delegate_->CanCreateWindow(
        opener, opener_url, opener_top_level_frame_url, source_origin,
        container_type, target_url, referrer, frame_name, disposition, features,
        additional_features, body, user_gesture, opener_suppressed,
        no_javascript_access);
  }
  return false;
}
void AtomBrowserClient::GetAdditionalAllowedSchemesForFileSystem(