The Symfony debug toolbar is coming from the SymfonyWebProfilerBundle and not directly included in the Debug component.

Also, because it's a bundle, you surely have to make some changes if you want use it as a standalone component (out of symfony).

Maybe look at the Laravel debug toolbar which is not a Symfony2 Bundle and can be easier to a adapt. It is built from the following package.

EDIT

The laravel toolbar is directly coming from maximebf/php-debugba