- 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/atom_browser_client.cc
base::CommandLine* command_line,
    int process_id) {
  std::string process_type = command_line->GetSwitchValueASCII("type");
  if (process_type != "renderer")
    return;
  
  if (!g_custom_service_worker_schemes.empty())
    command_line->AppendSwitchASCII(switches::kRegisterServiceWorkerSchemes,
                                    g_custom_service_worker_schemes);
#if defined(OS_WIN)
  
  PWSTR current_app_id;
  if (SUCCEEDED(GetCurrentProcessExplicitAppUserModelID(&current_app_id))) {
    command_line->AppendSwitchNative(switches::kAppUserModelId, current_app_id);
    CoTaskMemFree(current_app_id);
  }
#endif
  content::WebContents* web_contents = GetWebContentsFromProcessID(process_id);
  if (!web_contents)
    return;
  WebContentsPreferences::AppendExtraCommandLineSwitches(
      web_contents, command_line);
}
void AtomBrowserClient::DidCreatePpapiPlugin(