- Electron version: 1.2.2
- Operating system: Linux

This is a problem only in linux. It works in OSX.

``` javascript
win.hide()
win.capturePage(function(img){
 // never called
})
```

shell/browser/api/electron_api_web_contents.cc
const std::string& content) {
  auto it = saved_files_.find(url);
  if (it == saved_files_.end())
    return;
   Notify DevTools.
  base::Value url_value(url);
  inspectable_ontents_->CallClientFunction("DevToolsAPI.appendedToURL",
                                                &url_value, nullptr, nullptr);
  file_task_runner_->PostTask(
      FROM_HERE, base::BindOnce(&AppendToFile, it->second, content));
}
void WebContents::DevToolsRequestFileSystems() {