The Ronaldo Chop is a trick where it involves moving in a 45-60˚ or so direction quickly.
There are two ways to perform this trick. The trick is performed by players when there is a quick change of direction with the ball standing really close to the feet. The trick is performed by players with high Dribble Accuracy and Technique ratings and it' s usually done if there is a 45 degree change of direction after freezing the player with R1 or R2. However there isn't really a known button combination for this. However it is rumoured that it may be easier to perform if you do a drag back first.
A video of the trick performed by Thierry Henry.
The trick performed by Ibrahimovic after a R2 freeze.