Freeze the nsPromptService ContractID Now that nsIPromptService is frozen, we also need to freeze the nsPromptService ContractID. This needs to be done so that consumers can: 1) access the built-in nsIPromptService implementation, and 2) override the built-in nsIPromptService implementation to provide a non-XUL version. Our embedding examples show people how to override nsPromptService, and embedders are following our examples, so we need to freeze the ContractID. Here it is: #define NS_PROMPTSERVICE_CONTRACTID \ "@mozilla.org/embedcomp/prompt-service;1" We should probably create a header file named "nsCPromptService.h" for this, or since there are other components in the embedcomp module, we could put them all in one header file (e.g., the WindowWatcher service).

It looks like bz fixed this by adding the PromptService's ContractID to nsEmbedCID.h in bug 285080. *** This bug has been marked as a duplicate of 285080 ***