- Electron version: 1.2.1
- Operating system: Mac OS X

See also https://github.com/electron/electron/issues/5714

STR:
1. Start a webserver on localhost:port that serves a dummy index.html
2. Register a custom http protocol.
   
   ``` js
   electron.protocol.registerStandardSchemes(['foobar', 'http', 'https']);
   
   app.on('ready', function() {
     electron.protocol.registerHttpProtocol('foobar', (request, callback) => {
       const redirectPath = `http://localhost:port/index.html`;
       callback({ method: request.method, referrer: request.referrer, url: redirectPath });
     }, e => { if (e) { console.log(e); } });
   });
   ```
3. Either through devtools, or via some js in our index.html, have a single line that does `fetch('http://localhost:port/index.html')` or anything else from our server.

Results: as soon as `fetch` is called, the webview becomes black, and the devtools crash if they were open. No other visible error or stdout.

If devtools were open, they show this message: "Devtools was disconnected from the page.
Once page is reloaded, DevTools will automatically reconnect."

atom/browser/api/atom_api_protocol.cc
v8::Isolate* isolate, v8::Local<v8::ObjectTemplate> prototype) {
  mate::ObjectTemplateBuilder(isolate, prototype)
      .SetMethod("registerServiceWorkerSchemes",
                 &Protocol::RegisterServiceWorkerSchemes)
      .SetMethod("registerStringProtocol",
                 &Protocol::RegisterProtocol<URLRequestStringJob>)
      .SetMethod("registerBufferProtocol",
                 &Protocol::RegisterProtocol<URLRequestBufferJob>)
      .SetMethod("registerFileProtocol",
                 &Protocol::RegisterProtocol<URLRequestAsyncAsarJob>)
      .SetMethod("registerHttpProtocol",
                 &Protocol::RegisterProtocol<URLRequestFetchJob>)
      .SetMethod("unregisterProtocol", &Protocol::UnregisterProtocol)
      .SetMethod("isProtocolHandled", &Protocol::IsProtocolHandled)
      .SetMethod("interceptStringProtocol",
                 &Protocol::InterceptProtocol<URLRequestStringJob>)
      .SetMethod("interceptBufferProtocol",
                 &Protocol::InterceptProtocol<URLRequestBufferJob>)
      .SetMethod("interceptFileProtocol",
                 &Protocol::InterceptProtocol<URLRequestAsyncAsarJob>)
      .SetMethod("interceptHttpProtocol",
                 &Protocol::InterceptProtocol<URLRequestFetchJob>)
      .SetMethod("uninterceptProtocol", &Protocol::UninterceptProtocol);
}
}  
}  
namespace {
void RegisterStandardSchemes(