Merge "nit: Update VelocityTracker Javadoc" into udc-dev

 *

 * Use {@link #obtain} to retrieve a new instance of the class when you are going

 * to begin tracking.  Put the motion events you receive into it with

 * {@link #addMovement(MotionEvent)}.  When you want to determine the velocity call

 * {@link #computeCurrentVelocity(int)} and then call {@link #getXVelocity(int)}

 * and {@link #getYVelocity(int)} to retrieve the velocity for each pointer id.

 * {@link #addMovement(MotionEvent)}.  When you want to determine the velocity, call

 * {@link #computeCurrentVelocity(int)} and then call the velocity-getter methods like

 * {@link #getXVelocity(int)}, {@link #getYVelocity(int)}, or {@link #getAxisVelocity(int, int)}

 * to retrieve velocity for different axes and/or pointer IDs.

 */

public final class VelocityTracker {

    private static final SynchronizedPool<VelocityTracker> sPool =