* Output of `node_modules/.bin/electron --version`: v4.0.0
* Operating System (Platform and Version): macOS 10.14.2

* Output of `node_modules/.bin/electron --version` on last known working Electron version (if applicable): 2.0.7

### Expected behavior

I should be able to call `app.setAccessibilitySupportEnabled(true)` during initialization, and the application should start and stay open.

### Actual behavior

The application starts and exits immediately if `app.setAccessibilitySupportEnabled(true)` is called during initialization. Same for passing in `false`.

### How to reproduce

Here is a simple project that shows this error. The application behaves as expected (does not exit immediately) when this line is commented out:
https://github.com/marisademeglio/electron4-setA11yTreeEnabled/blob/master/src/main/main.js#L27

  $ git clone https://github.com/marisademeglio/electron4-setA11yTreeEnabled.git
  $ yarn install
  $ yarn start

atom/browser/api/atom_api_app.cc
content::RenderFrameHost* opener,
    const GURL& opener_url,
    const GURL& opener_top_level_frame_url,
    const GURL& source_origin,
    content::mojom::WindowContainerType container_type,
    const GURL& target_url,
    const content::Referrer& referrer,
    const std::string& frame_name,
    WindowOpenDisposition disposition,
    const blink::mojom::WindowFeatures& features,
    const std::vector<std::string>& additional_features,
    const scoped_refptr<network::ResourceRequestBody>& body,
    bool user_gesture,
    bool opener_suppressed,
    bool* no_javascript_access) {
  v8::Locker locker(isolate());
  v8::HandleScope handle_scope(isolate());
  content::WebContents* web_contents =
      content::WebContents::FromRenderFrameHost(opener);
  if (web_contents) {
    auto api_web_contents = WebContents::From(isolate(), web_contents);
    
    if (!api_web_contents.IsEmpty()) {
      api_web_contents->OnCreateWindow(target_url, referrer, frame_name,
                                       disposition, additional_features, body);
    }
  }
  return false;
}
void App::AllowCertificateError(