Refresh display lists when turning off layers rendering.

     * @hide

     */

    public void setChildrenLayersEnabled(boolean enabled) {

        if (enabled != mDrawLayers) {

            mDrawLayers = enabled;

            invalidate(true);

            // We need to invalidate any child with a layer. For instance,

            // if a child is backed by a hardware layer and we disable layers

            // the child is marked as not dirty (flags cleared the last time

            // the child was drawn inside its layer.) However, that child might

            // never have created its own display list or have an obsolete

            // display list. By invalidating the child we ensure the display

            // list is in sync with the content of the hardware layer.

            for (int i = 0; i < mChildrenCount; i++) {

                View child = mChildren[i];

                if (child.mLayerType != LAYER_TYPE_NONE) {

                    child.invalidate(true);

                }

            }

        }

    }

    /**