Android Activity ActionMode Callback

两个ActionMode在Activity的回调，记一下。

注意这两个callback发生的时机都是onXXX,即事件是发生了，但是还没完成，

就是ActionMode还没有完全的出现/消失.

因此，某些时候，要做一些明确在ActionMode出现/消失的操作时，要把这些操作Delay到下一个slice.

    /**     * Notifies the Activity that an action mode has been started.     * Activity subclasses overriding this method should call the superclass implementation.     *     * @param mode The new action mode.     */    @Override    public void onActionModeStarted(ActionMode mode) {    }    /**     * Notifies the activity that an action mode has finished.     * Activity subclasses overriding this method should call the superclass implementation.     *     * @param mode The action mode that just finished.     */    @Override    public void onActionModeFinished(ActionMode mode) {    }