remove the useless MigratePrefs method. change upgradePrefs() into UpgradePrefs() and make it part of the nsIMsgAccountManager interface, so alecf can call it from js.

mailnews/base/public/nsIMsgAccountManager.idl

@@ -112,7 +112,7 @@ interface nsIMsgAccountManager : nsISupports {
 
   void WriteToFolderCache(in nsIMsgFolderCache folderCache);
 
-  /* search for 4.x prefs, and migrate to 5.0 prefs */
-  void MigratePrefs();
+  /* search for 4.x mailnews prefs, and migrate to 5.0 prefs */
+  void UpgradePrefs();
 };
 

mailnews/base/src/nsMsgAccountManager.cpp

@@ -296,8 +296,6 @@ private:
   static PRBool writeFolderCache(nsHashKey *aKey, void *aData, void *closure);
 
   // methods for migration / upgrading
-  nsresult upgradePrefs();
-
   nsresult createSpecialFile(nsFileSpec & dir, const char *specialFileName);
   nsresult CopyIdentity(nsIMsgIdentity *srcIdentity, nsIMsgIdentity *destIdentity);
   
@@ -912,7 +910,7 @@ nsMsgAccountManager::LoadAccounts()
 #ifdef DEBUG_ACCOUNTMANAGER
     printf("No accounts. I'll try to migrate 4.x prefs..\n");
 #endif
-    rv = upgradePrefs();
+    rv = UpgradePrefs();
     return rv;
   }
 
@@ -985,19 +983,6 @@ nsMsgAccountManager::WriteToFolderCache(nsIMsgFolderCache *folderCache)
 	return folderCache->Close();
 }
 
-nsresult
-nsMsgAccountManager::MigratePrefs()
-{
-#ifdef DEBUG_ACCOUNTMANAGER
-	printf("nsMsgAccountManager::MigratePrefs()\n");
-#endif
-
-	// do nothing right now.
-	// right now, all the migration happens when we don't find
-	// the mail.accountmanager.accounts pref in LoadAccounts()
-	return NS_OK;
-}
-
 nsresult
 nsMsgAccountManager::createKeyedAccount(const char* key,
                                         nsIMsgAccount ** aAccount)
@@ -1110,8 +1095,8 @@ nsMsgAccountManager::createSpecialFile(nsFileSpec & dir, const char *specialFile
 	return rv;
 }
 
-nsresult
-nsMsgAccountManager::upgradePrefs()
+NS_IMETHODIMP
+nsMsgAccountManager::UpgradePrefs()
 {
     nsresult rv;
     PRInt32 oldMailType;