OnPaint use const RectList& dirtyRects

[Lecrapouille]

void GDCef::RenderHandler::OnPaint(CefRefPtr<CefBrowser> browser, PaintElementType type,
                                   const RectList& dirtyRects, const void* buffer,
                                   int width, int height)

Manage dirtyRects and can we use poolthreads to parallelize ?