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* Electron version: 1.6.1
* Operating system: macOS

### Expected behavior

navigator.geolocation.getCurrentPosition runs in background

### Actual behavior

the entire UI is frozen

### How to reproduce

```js
    navigator.geolocation.getCurrentPosition((pos) => {
      console.log('POS: ' + pos);
    }, (err) => {
      console.log('Geolocation error: ', err);
    }, {enableHighAccuracy: false});
```
atom/browser/common_web_contents_delegate.h
#ifndef ATOM_BROWSER_COMMON_WEB_CONTENTS_DELEGATE_H_
#define ATOM_BROWSER_COMMON_WEB_CONTENTS_DELEGATE_H_
#include <map>
#include <string>
#include <vector>
#include "brightray/browser/devtools_file_system_indexer.h"
#include "brightray/browser/inspectable_web_contents_delegate.h"
#include "brightray/browser/inspectable_web_contents_impl.h"
#include "brightray/browser/inspectable_web_contents_view_delegate.h"
#include "content/public/browser/web_contents_delegate.h"
using brightray::DevToolsFileSystemIndexer;
namespace atom {
class AtomBrowserContext;