* **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
user_agent_override_ = user_agent;
}
void AtomBrowserClient::RegisterNonNetworkNavigationURLLoaderFactories(
    int frame_tree_node_id,
    NonNetworkURLLoaderFactoryMap* factories) {
  content::WebContents* web_contents =
      content::WebContents::FromFrameTreeNodeId(frame_tree_node_id);
  api::ProtocolNS* protocol = api::ProtocolNS::FromWrappedClass(
      v8::Isolate::GetCurrent(), web_contents->GetBrowserContext());
  if (protocol)
    protocol->RegisterURLLoaderFactories(factories);
}
void AtomBrowserClient::RegisterNonNetworkSubresourceURLLoaderFactories(
    int render_process_id,
    int render_frame_id,
    NonNetworkURLLoaderFactoryMap* factories) {
  
  if (!base::FeatureList::IsEnabled(network::features::kNetworkService))
    return;
  content::RenderFrameHost* frame_host =
      content::RenderFrameHost::FromID(render_process_id, render_frame_id);
  content::WebContents* web_contents =
      content::WebContents::FromRenderFrameHost(frame_host);
  api::ProtocolNS* protocol = api::ProtocolNS::FromWrappedClass(
      v8::Isolate::GetCurrent(), web_contents->GetBrowserContext());
  if (protocol)
    protocol->RegisterURLLoaderFactories(factories);
}
bool AtomBrowserClient::WillCreateURLLoaderFactory(