- Electron version:
  We are using node 5.10.0, Chrome 49.0.2623.75, and Electron 1.0.1. 
- Operating system:
  Mac OS X 10.11.3 (15D21)

Trying to use the [Web Bluetooth APIs](https://developers.google.com/web/updates/2015/07/interact-with-ble-devices-on-the-web?hl=en#scan-for-bluetooth-devices) but when I run the Web Bluetooth demo code, the callbacks fail with the error:

`Argh! NotFoundError: User cancelled the requestDevice() chooser.`

main.js code:

```
// Module to control application life.
const {app} = electron;

// @link https://github.com/electron/electron/blob/master/docs/api/chrome-command-line-switches.md
app.commandLine.appendSwitch('enable-web-bluetooth', true);
```

Index.html code:

```
<a href="#" onclick="run();" class="scanDevices">Scan</a>
    <script>
    function run() {
        var filters = [{
    services: [0x1800, 0x1801, 0x1812]
  }];
          console.log('Requesting Bluetooth Device...');
  navigator.bluetooth.requestDevice({filters: filters})
  .then(device => {
    console.log('> Name:             ' + device.name);
    console.log('> Id:               ' + device.id);
    console.log('> UUIDs:            ' + device.uuids.join('\n' + ' '.repeat(20)));
    console.log('> Connected:        ' + device.gatt.connected);
  })
  .catch(error => {
    console.log('Argh! ' + error);
  });
  }
    </script>
```

Reference:
https://github.com/electron/electron/blob/master/atom/browser/atom_permission_manager.cc#L93

atom/browser/api/atom_api_web_contents.h
class WebViewGuestDelegate;
namespace api {
class WebContents : public mate::TrackableObject<WebContents>,
                    public CommonWebContentsDelegate,
                    public content::WebContentsObserver {
 public:
  
  using PrintToPDFCallback =
      base::Callback<void(v8::Local<v8::Value>, v8::Local<v8::Value>)>;
  
  static mate::Handle<WebContents> CreateFrom(
      v8::Isolate* isolate, content::WebContents* web_contents);
  
  static mate::Handle<WebContents> Create(
      v8::Isolate* isolate, const mate::Dictionary& options);
  static void BuildPrototype(v8::Isolate* isolate,
                             v8::Local<v8::ObjectTemplate> prototype);
  int GetID() const;
  bool Equal(const WebContents* web_contents) const;
  void LoadURL(const GURL& url, const mate::Dictionary& options);
  void DownloadURL(const GURL& url);
  GURL GetURL() const;
  base::string16 GetTitle() const;
  bool IsLoading() const;
  bool IsLoadingMainFrame() const;
  bool IsWaitingForResponse() const;
  void Stop();
  void ReloadIgnoringCache();
  void GoBack();