- 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
double factor) {
  if (factor < std::numeric_limits<double>::epsilon()) {
    thrower.ThrowError("'zoomFactor' must be a double greater than 0.0");
    return;
  }
  auto level = blink::PageZoomFactorToZoomLevel(factor);
  SetZoomLevel(level);
}
double WebContents::GetZoomFactor() const {
  auto level = GetZoomLevel();
  return blink::PageZoomLevelToZoomFactor(level);
}
void WebContents::SetTemporaryZoomLevel(double level) {
  zoom_controller_->SetTemporaryZoomLevel(level);
}
void WebContents::DoGetZoomLevel(
    electron::mojom::ElectronBrowser::DoGetZoomLevelCallback callback) {
  std::move(callback).Run(GetZoomLevel());
}
std::vector<base::FilePath> WebContents::GetPreloadPaths() const {
  auto result = SessionPreferences::GetValidPreloads(GetBrowserContext());
  if (auto* web_preferences = WebContentsPreferences::From(ontents())) {
    base::FilePath preload;
    if (web_preferences->GetPreloadPath(&preload)) {
      result.emplace_back(preload);
    }
  }
  return result;
}
v8::Local<v8::Value> WebContents::GetWebPreferences(