The inline editor is not scrolling inside scrollable div

[cytsunny]

Steps to reproduce

1. Create a scrollable div
2. Inside that scrollable div, add content so that it can actually scroll
3. Put a inline-editor into to div by setting one div into contenteditable.

Reference: ​https://jsfiddle.net/pteryvk3/6/

Expected result

The inline editor should scroll with the div and behaves as in official demo page. ​http://ckeditor.com/demo#inline

Actual result

It doesn't scroll.

Other details (browser, OS, CKEditor version, installed plugins)

This has been tested using Internet Explorer 11.212.10586, Chrome 49.0.2623.112, Firefox 43.0.1, Edge 25.10586.0.0 under Windows 10 CDN is used to include the editor and no plugin is used.

[Jakub Ś]

Problem can be reproduced from CKEditor 4.0. At first I thought that perhaps position:absolute might have something to do with this problem but it seems that only overflow:scroll causes the problem for CKEditor toolbar.