- 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
const content::LoadCommittedDetails& details,
    const content::FrameNavigateParams& params) {
  if (details.is_navigation_to_different_page())
    Emit("did-navigate", params.url);
  else if (details.is_in_page)
    Emit("did-navigate-in-page", params.url);
}
void WebContents::TitleWasSet(content::NavigationEntry* entry,
                              bool explicit_set) {
  if (entry)
    Emit("-page-title-updated", entry->GetTitle(), explicit_set);
  else
    Emit("-page-title-updated", "", explicit_set);
}
void WebContents::DidUpdateFaviconURL(
    const std::vector<content::FaviconURL>& urls) {
  std::set<GURL> unique_urls;
  for (auto iter = urls.begin(); iter != urls.end(); ++iter) {
    if (iter->icon_type != content::FaviconURL::FAVICON)
      continue;
    const GURL& url = iter->icon_url;
    if (url.is_valid())
      unique_urls.insert(url);
  }
  Emit("page-favicon-updated", unique_urls);
}
void WebContents::DevToolsReloadPage() {