getCurrentURL of current frame not return the URL of the frame

[gssatcc]

Expected Behavior -

Until recent releases of chromedriver it was possible to get the current URL of selected frame

Actual Behavior -

At the moment the method there is no way to getCurrentURL of the frame but only on the main window.

Steps to reproduce -

1. Go to URL with some iframe
2. Select the iframe
3. Use method like:
   currentUrl() {
   return browser.driver.getCurrentUrl();
   }
   to get current URL

[AutomatedTester]

This is expected behaviour. If you require that frames url use executeScript('return document.location.href');