* 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
scoped_refptr<util::Promise> promise,
                         gfx::Image* icon) {
  v8::Locker locker(isolate);
  v8::HandleScope handle_scope(isolate);
  if (icon && !icon->IsEmpty()) {
    promise->Resolve(*icon);
  } else {
    promise->RejectWithErrorMessage("Failed to get file icon.");
  }
}
}  
App::App(v8::Isolate* isolate) {
  static_cast<AtomBrowserClient*>(AtomBrowserClient::Get())->set_delegate(this);
  Browser::Get()->AddObserver(this);
  content::GpuDataManager::GetInstance()->AddObserver(this);
  base::ProcessId pid = base::GetCurrentProcId();
  auto process_metric = std::make_unique<atom::ProcessMetric>(
      content::PROCESS_TYPE_BROWSER, pid,
      base::ProcessMetrics::CreateCurrentProcessMetrics());
  app_metrics_[pid] = std::move(process_metric);
  Init(isolate);
}
App::~App() {