DrawTextManager::ShutdownRendering

void ShutdownRendering(bool wait);

ShutdownRendering shuts down rendering of the movie; it can be called before Movie is released to avoid render-thread block in destructor. 

After ShutdownRendering(false), IsShutdownRenderingComplete call can be used to determine when shutdown is complete. 

Advance, Invoke or other state-modifying functions should NOT be called once shutdown has started.