Merge "Use launcher surface when removing launch target" into sc-dev

     * Sets the specified app target surface to apply the blur to.

     */

    public void setSurface(SurfaceControl surface) {

        // Set launcher as the SurfaceControl when we don't need an external target anymore.

        if (surface == null) {

            ViewRootImpl viewRootImpl = mLauncher.getDragLayer().getViewRootImpl();

            surface = viewRootImpl != null ? viewRootImpl.getSurfaceControl() : null;

        }

        if (mSurface != surface) {

            mSurface = surface;

            if (surface != null) {