* 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
std::vector<mate::Dictionary> result;
  int processor_count = base::SysInfo::NumberOfProcessors();
  for (const auto& process_metric : app_metrics_) {
    mate::Dictionary pid_dict = mate::Dictionary::CreateEmpty(isolate);
    mate::Dictionary cpu_dict = mate::Dictionary::CreateEmpty(isolate);
    pid_dict.SetHidden("simple", true);
    cpu_dict.SetHidden("simple", true);
    cpu_dict.Set(
        "percentCPUUsage",
        process_metric.second->metrics->GetPlatformIndependentCPUUsage() /
            processor_count);
#if !defined(OS_WIN)
    cpu_dict.Set("idleWakeupsPerSecond",
                 process_metric.second->metrics->GetIdleWakeupsPerSecond());
#else
    
    
    
    cpu_dict.Set("idleWakeupsPerSecond", 0);
#endif
    pid_dict.Set("cpu", cpu_dict);
    pid_dict.Set("pid", process_metric.second->pid);
    pid_dict.Set("type", content::GetProcessTypeNameInEnglish(
                             process_metric.second->type));
    result.push_back(pid_dict);
  }
  return result;
}
v8::Local<v8::Value> App::GetGPUFeatureStatus(v8::Isolate* isolate) {