- 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
content::WebContents* ontents)
    : content::WebContentsObserver(ontents),
      type_(Type::kRemote),
      id_(GetAllWebContents().Add(this)),
      devtools_file_system_indexer_(new DevToolsFileSystemIndexer),
      file_task_runner_(
          base::ThreadPool::CreateSequencedTaskRunner({base::MayBlock()}))
#if BUILDFLAG(ENABLE_PRINTING)
      ,
      print_task_runner_(CreatePrinterHandlerTaskRunner())
#endif
{
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
  
  extensions::ViewType view_type = extensions::GetViewType(ontents);
  if (view_type != extensions::VIEW_TYPE_INVALID) {