- 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.cc
#include "content/public/browser/site_instance.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/context_menu_params.h"
#include "native_mate/dictionary.h"
#include "native_mate/object_template_builder.h"
#include "net/http/http_response_headers.h"
#include "net/url_request/static_http_user_agent_settings.h"
#include "net/url_request/url_request_context.h"
#include "third_party/WebKit/public/web/WebInputEvent.h"
#include "third_party/WebKit/public/web/WebFindOptions.h"
#include "ui/base/l10n/l10n_util.h"
#include "atom/common/node_includes.h"
namespace {
struct PrintSettings {
  bool silent;
  bool print_background;
};
void SetUserAgentInIO(scoped_refptr<net::URLRequestContextGetter> getter,
                      std::string accept_lang,
                      std::string user_agent) {
  getter->GetURLRequestContext()->set_http_user_agent_settings(
      new net::StaticHttpUserAgentSettings(
          net::HttpUtil::GenerateAcceptLanguageHeader(accept_lang),
          user_agent));
}
}  
namespace mate {
template<>
struct Converter<atom::SetSizeParams> {
  static bool FromV8(v8::Isolate* isolate,