In Pathfinder, the Ninja is an alternate class for the core Rogue class. One of its abilities is Light Step:
At 6th level, a ninja learns to move while barely touching the surface underneath her. As a full-round action, she can move up to twice her speed, ignoring difficult terrain. While moving in this way, any surface will support her, no matter how much she weighs. This allows her to move across water, lava, or even the thinnest tree branches. She must end her move on a surface that can support her normally. She cannot move across air in this way, nor can she walk up walls or other vertical surfaces. When moving in this way, she does not take damage from surfaces or hazards that react to being touched, such as lava or caltrops, nor does she need to make Acrobatics checks to avoid falling on slippery or rough surfaces. Finally, when using light steps, the ninja ignores any mechanical traps that use a location-based trigger.
The description for the Acrobatics skill says that a character can move through a threatened square without provoking an attack of opportunity via their acobatics:
In addition, you can move through a threatened square without provoking an attack of opportunity from an enemy by using Acrobatics. When moving in this way, you move at half speed. You can move at full speed by increasing the DC of the check by 10. You cannot use Acrobatics to move past foes if your speed is reduced due to carrying a medium or heavy load or wearing medium or heavy armor. If an ability allows you to move at full speed under such conditions, you can use Acrobatics to move past foes. You can use Acrobatics in this way while prone, but doing so requires a full-round action to move 5 feet, and the DC is increased by 5. If you attempt to move through an enemy's space and fail the check, you lose the move action and provoke an attack of opportunity.
Is it correct that a Ninja using Light Steps would typically provoke an attack of opportunity, but that they can avoid it if they make an additional (and immediate, free) Acrobatics skill check?