From that teardown, it looks like a solid charger with an unchallenging design. (I.e. they didn't try to make it small.) I think it uses the iWatt 1699 control chip: https://www.dialog-semiconductor.com/products/acdc-conversio...

Big Clive also did a fairly comprehensive teardown of the IKEA charger and was pleasantly surprised with the design: https://youtu.be/uRe9w5PKmsE

He also confirms that the control chip is a 1699-02.