On Macbook, when user performs 2-finger horizontal swipe for tab history navigation, a nice little arrow animation appears, which has two states:
1) Gesture started but not completed: arrow will transition into view. If user lifts fingers, action will not be performed
2) Gesture counts as completed: arrow gets filled with color. If user lifts fingers, action will be performed
It will be good to use haptic engine of Macbook trackpad to inform user about transition between these 2 states. Light virtual trackpad "click" will let user know that gesture was registered successfully, and they don't need to continue the swipe; that they can lift fingers now and get the desired action performed (back/forward navigation in this case).
I got this idea from Swish utility for Mac, which uses trackpad haptic feedback in a very similar manner.