- 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 gin_helper::Dictionary preferences) {
  v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
  v8::Locker locker(isolate);
  v8::HandleScope handle_scope(isolate);
  
  
  pending_child_web_preferences_.Reset(isolate, preferences.GetHandle());
}
content::WebConbContents::CreateCustomWebContents(
    content::RenderFrameHost* opener,
    content::SiteInstance* source_site_instance,
    bool is_new_browsing_instance,
    const GURL& opener_url,
    const std::string& frame_name,
    const GURL& target_url,
    const std::string& partition_id,
    content::SessionStorageNamespace* session_storage_namespace) {
  return nullptr;
}
void WebContents::AddNewContents(