[Edge] Editor viewport is scrolled back to the top when focusing editor for the first time.

[kkrzton]

Steps to reproduce

1. Go to ​http://ckeditor.com/demo.
2. Scroll editor viewport without focusing editor (e.g. using mouse wheel).
3. Click inside editor content to focus editor.

Expected result

The editor is focused and caret is placed on the position of the click.

Actual result

The editor viewport scrolls to the top and caret is placed on the beginning of the content.

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

Edge (Edge 38.14393, EdgeHTML 14.14393) - it does not happen in previous versions of Edge browser.

[kkrzton]

There is similar issue #14556 (but it occurs in the previous Edge version).

[kkrzton]

While investigating #14825 I found that the scroll effect after focusing editor mentioned in this issue is caused by selectionChange event ​fired here.

[Jakub Ś]

Issue has been reported on Github as well - ​https://github.com/ckeditor/ckeditor-dev/issues/504.