* 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
AtomBrowserClient::CreateQuotaPermissionContext() {
  return new AtomQuotaPermissionContext;
}
content::GeneratedCodeCacheSettings
AtomBrowserClient::GetGeneratedCodeCacheSettings(
    content::BrowserContext* context) {
  
  base::FilePath cache_path = context->GetPath();
  
  
  
  return content::GeneratedCodeCacheSettings(true, 0, cache_path);
}
void AtomBrowserClient::AllowCertificateError(
    content::WebContents* web_contents,
    int cert_error,
    const net::SSLInfo& ssl_info,
    const GURL& request_url,
    content::ResourceType resource_type,
    bool strict_enforcement,
    bool expired_previous_decision,
    const base::Callback<void(content::CertificateRequestResultType)>&
        callback) {
  if (delegate_) {
    delegate_->AllowCertificateError(
        web_contents, cert_error, ssl_info, request_url, resource_type,
        strict_enforcement, expired_previous_decision, callback);
  }
}
void AtomBrowserClient::SelectClientCertificate(