Triggers a repaint of the VisualElement on the next frame. This method is called internally when a change occurs that requires a repaint, such as when UIElements.BaseField_1.value is changed or the text in a Label. If you are implementing a custom control, you can call this method to trigger a repaint when a change occurs that requires a repaint such as when using generateVisualContent to render a mesh and the mesh data has now changed.