override IID method

mailnews/local/public/nsIMailboxUrl.h

@@ -37,6 +37,10 @@
 class nsIMailboxUrl : public nsIURL
 {
 public:
+  static const nsIID& IID() {
+    static nsIID iid = NS_IMAILBOXURL_IID;
+    return iid;
+  }
 
 	/////////////////////////////////////////////////////////////////////////////// 
 	// Getters and Setters for the mailbox specific event sinks to bind to to your url

mailnews/local/public/nsIPop3URL.h

@@ -36,6 +36,10 @@
 class nsIPop3URL : public nsIURL
 {
 public:
+ static const nsIID& IID() {
+    static nsIID iid = NS_IPOP3URL_IID;
+    return iid;
+  }
 	/////////////////////////////////////////////////////////////////////////////// 
 	// Getters and Setters for the news specific event sinks to bind to to your url
 	///////////////////////////////////////////////////////////////////////////////