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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/api/atom_api_web_contents.cc
const base::FilePath& path) {
  if (path.empty()) {
    args->ThrowError("path cannot be empty");
    return;
  }
  DevToolsRemoveFileSystem(path);
}
void WebContents::Undo() {
  web_contents()->Undo();
}
void WebContents::Redo() {
  web_contents()->Redo();
}
void WebContents::Cut() {
  web_contents()->Cut();
}
void WebContents::Copy() {
  web_contents()->Copy();
}
void WebContents::Paste() {
  web_contents()->Paste();
}
void WebContents::PasteAndMatchStyle() {