'DelegateImplementation' is a variation of 'ManuallyImplement'. 'ManuallyImplement' emits the interface method, but suppresses the Java and native-code implementation. The latter shall be implemented manually by the user. 'DelegateImplementation' emits the interface method, and the renamed Java and native-code implementation. Both can be called from the manual user implementation, hence delegation.
Editing troubles, moved to Bug 1144.