* 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
content::RenderFrame* render_frame) {
  new PepperHelper(render_frame);
  new ContentSettingsObserver(render_frame);
  new printing::PrintWebViewHelper(render_frame);
  
  
  blink::WebSecurityPolicy::registerURLSchemeAsAllowingServiceWorkers("file");
  
  blink::resetPluginCache();
  
  blink::WebSecurityPolicy::addOriginAccessWhitelistEntry(
      GURL(kPdfViewerUIOrigin), "file", "", true);
  
  std::vector<std::string> secure_schemes_list =
      ParseSchemesCLISwitch(switches::kSecureSchemes);
  for (const std::string& secure_scheme : secure_schemes_list)
    blink::WebSecurityPolicy::registerURLSchemeAsSecure(
        blink::WebString::fromUTF8(secure_scheme));
}
void RendererClientBase::RenderViewCreated(content::RenderView* render_view) {