- 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
if (source && source->GetOutermostWebContents() == source) {
     If this is the outermost web contents and the user has tabbed or
     shift + tabbed through all the elements, reset the focus back to
     the first or last element so that it doesn't stay in the body.
    source->FocusThroughTabTraversal(reverse);
    return true;
  }
  return false;
}
content::PictureInPictureResult WebContents::EnterPictureInPicture(
    content::WebContents* ontents,
    const viz::SurfaceId& surface_id,
    const gfx::Size& natural_size) {
#if BUILDFLAG(ENABLE_PICTURE_IN_PICTURE)
  return PictureInPictureWindowManager::GetInstance()->EnterPictureInPicture(
      ontents, surface_id, natural_size);
#else
  return content::PictureInPictureResult::kNotSupported;
#endif
}
void WebContents::ExitPictureInPicture() {
#if BUILDFLAG(ENABLE_PICTURE_IN_PICTURE)
  PictureInPictureWindowManager::GetInstance()->ExitPictureInPicture();
#endif
}
void WebContents::DevToolsSaveToFile(const std::string& url,