* Electron version: 1.6.2
* Operating system: macOS 10.12.3 (Sierra)

### Expected behavior

Scrollable elements should bounce (rubber band) when reaching the bounds if a window's `webPreferences.scrollBounce = true`

### Actual behavior

Bouncing does not happen

### How to reproduce

```javascript
var win = new BrowserWindow({
    width:800,
    height:600,
    webPreferences:{
        scrollBounce:true
    }
});
```

atom/renderer/renderer_client_base.cc
#include "atom/renderer/renderer_client_base.h"
#include <string>
#include <vector>
#include "atom/common/atom_constants.h"
#include "atom/common/color_util.h"
#include "atom/common/native_mate_converters/value_converter.h"
#include "atom/common/options_switches.h"
#include "atom/renderer/content_settings_observer.h"
#include "atom/renderer/guest_view_container.h"
#include "atom/renderer/preferences_manager.h"
#include "base/command_line.h"