This class implements IUnknown by delegating to the owner object's IUnknown.
template< class Base > class CComContainedObject : public Base
ATL uses CComContainedObject in classes CComAggObject, CComPolyObject, and CComCachedTearOffObject. CComContainedObject implements IUnknown by delegating to the owner object's IUnknown. (The owner is either the outer object of an aggregation, or the object for which a tear-off interface is being created.) CComContainedObject calls CComObjectRootEx's OuterQueryInterface, OuterAddRef, and OuterRelease, all inherited through Base.