Using the unified toolbar on Mac with the raster engine results with the wrong painting

The unified toolbar is currently not supported with the raster engine.

When using the unified toolbar on Mac OS X with the raster engine, all the updates to the items in the toolbar are done in the content view. As a result, we have 2 toolbars, and the unified one is only updated when the window is updated (when we resize for example).

The unified toolbar is now drawn using the native engine. We must find a way to redirect all updates to the unified toolbar when necessary.