code: function autoCleanup (self, cleanupFn) {
    if (self.mousedown || self.lastRipple) {
      self.mousedown = false;
      self.$mdUtil.nextTick(angular.bind(self, cleanupFn), false);
    }
  }
docs: Either remove or unlock any remaining ripples when the user mouses off of the element (either by
  mouseup or mouseleave event)