Merge "Clarify that `Message#what` is 0 unless otherwise set." into main

    /**

     * Remove any pending posts of messages with code 'what' that are in the

     * message queue.

     *

     * Note that `Message#what` is 0 unless otherwise set.

     * When calling `postMessage(Runnable)` or `postAtTime(Runnable, long)`,

     * the `Runnable` is internally wrapped with a `Message` whose `what` is 0.

     * Calling `removeMessages(0)` will remove all messages without a `what`,

     * including posted `Runnable`s.

     */

    public final void removeMessages(int what) {

        mQueue.removeMessages(this, what, null);

     * what this message is about. Each {@link Handler} has its own name-space

     * for message codes, so you do not need to worry about yours conflicting

     * with other handlers.

     *

     * If not specified, this value is 0.

     * Use values other than 0 to indicate custom message codes.

     */

    public int what;