[TI] Select all on only table content creates native selection.

[kkrzton]

Steps to reproduce

1. Go to ​http://tests.ckeditor.dev:1030/tests/plugins/tableselection/manual/integrations/selectall/table.
2. Follow the scenario (with Cmd + A).
3. When releasing Cmd + A, release A and after some time release Cmd.

Expected result

The table is faked selected.

Actual result

Native selection is visible.

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

OS X, tested on Safari, Chrome. Works fine on Firefox.

Additionally on Safari, error is thrown: TypeError: null is not an object (evaluating 'e.getChild(f-1).type'). If Cmd + A is release at once it works fine. Seems to be working fine on Windows where select all is fired after releasing A. On OS X it is fired after releasing Cmd.