* **Electron Version** (output of `node_modules/.bin/electron --version`):
  * 3.0.6
* **Operating System** (Platform and Version):
  * macOS 10.14

### Expected Behavior
a `new-window` event fires

### Actual behavior
a `did-fail-load` fires with errorCode -3

### To Reproduce
```sh
$ git clone git@github.com:chrismohr/no-new-window.git -b master
$ cd no-new-window/
$ npm i && npm start
```

atom/browser/atom_browser_client.cc
int process_id,
    AtomBrowserClient::ProcessPreferences prefs) {
  base::AutoLock auto_lock(process_preferences_lock_);
  process_preferences_[process_id] = prefs;
}
void AtomBrowserClient::RemoveProcessPreferences(int process_id) {
  base::AutoLock auto_lock(process_preferences_lock_);
  process_preferences_.erase(process_id);
}
bool AtomBrowserClient::IsProcessObserved(int process_id) const {
  base::AutoLock auto_lock(process_preferences_lock_);
  return process_preferences_.find(process_id) != process_preferences_.end();
}
bool AtomBrowserClient::IsRendererSandboxed(int process_id) const {