Page is scrolling down when I click on any panel element

[Alex]

Steps to reproduce

1. Go to ​http://ckeditor.com/demo#full-page
2. Scroll page, so that editor appear in bottom of the screen.
3. In editor, click "Source", delete all HTML content and Copy&Paste new content from here: ​http://pastebin.com/raw/U0QHSidz
4. Сlick "Source" to switch from source mode to visual.
5. Click any panel element, for example "B" (Bold) button.

Expected result

Page is not scrolled.

Actual result

Page is scrolled down.

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

If content have many lines, then page is scrolled very far. I have usual Chromium browser 49.0.2623.108

[Alex]

test content for editor

[Jakub Ś]

Problem can be reproduced from CKEditor 4.4.6 in Blink browsers only (Safari works fine). It looks as if CKEditor was trying to scroll the page to the middle of the content.

NOTE: In my test I have added extra margin-top to footer in sample page to show problem better.