Cordova.exec(..) not working when called from an iframe inside the webview

Cordova.exec(..) not working when called from an iframe inside the web view.

I could able to see the function Cordova.exec(..) is getting called, but it's not delegating the request to native.

When i load the same page directly in the web view, it's working properly.
I couldn't figure out what's the difference between both the scenarios.

Note: Popup (iframe) is not loosing context after calling cordova.exec(...).