- 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
namespace {
using electron::api::GetAllWebContents;
using electron::api::WebContents;
gin::HContents> WebContentsFromID(v8::Isolate* isolate, int32_t id) {
  WebContents* contents = WebContents::FromID(id);
  return contents ? gin::CreateHandle(isolate, contents)
                  : gin::HContents>();
}
std::vector<gin::HContents>> GetAllWebContentsAsV8(
    v8::Isolate* isolate) {
  std::vector<gin::HContents>> list;
  for (auto iter = base::IDMap<WebContents*>::iterator(&GetAllWebContents());
       !iter.IsAtEnd(); iter.Advance()) {
    list.push_back(gin::CreateHandle(isolate, iter.GetCurrentValue()));
  }
  return list;
}
void Initialize(v8::Lobject> exports,
                v8::Local<v8::Value> unused,
                v8::Local<v8::Context> context,
                void* priv) {
  v8::Isolate* isolate = context->GetIsolate();
  gin_helper::Dictionary dict(isolate, exports);
  dict.Set("WebContents", WebContents::GetConstructor(context));
  dict.SetMethod("fromId", &WebContentsFromID);
  dict.SetMethod("getAllWebContents", &GetAllWebContentsAsV8);
}
e
NODULE_CONTEXT_AWARE(electron_browser_ontents, Initialize)