Replaced m_OwnsTexture with (m_TextureOwner == null).
Changed SourceFilter and OutputDummy OutputSize to use Renderer.Input/OutputSize which is available at the point where OnInput/OutputSizeChanged() is called.
This allows us to move AllocateTextures output Render() which should reduce CPU usage.
Refactored RenderScript to force implementors to return IFilter via GetFilter();