Safari: Editor in autogrow does not render nicely when fullPage is set to true

[Jakub Ś]

1. Set config.fullPage=true;
2. Load the autogrow sample
3. Start pressing enter rapidly. I nothing unusual has happened yet scroll up and start pressing enters again.

Result:
From rev [7018] - editor contents sometimes goes out editor border (see 7018.png)

From rev [7056] - editor is not rendered nicely (see 7056.png). Of course if you minimize the browser for a moment editor will come back to its normal look.

[Jakub Ś]

This ticked was found when reproducing #7984

[Jakub Ś]

This problem can no longer be reproduced in CKEditor 4.x and latest Safari