nsISupports interfaces need to be threadsafe for import. r=sspitzer

mailnews/base/src/nsMsgMailSession.cpp

@@ -30,7 +30,7 @@
 #include "nsIMsgStatusFeedback.h"
 #include "nsIMsgWindow.h"
 
-NS_IMPL_ISUPPORTS1(nsMsgMailSession, nsIMsgMailSession);
+NS_IMPL_THREADSAFE_ISUPPORTS1(nsMsgMailSession, nsIMsgMailSession);
 
 static NS_DEFINE_IID(kIFileLocatorIID,      NS_IFILELOCATOR_IID);
 static NS_DEFINE_CID(kFileLocatorCID,       NS_FILELOCATOR_CID);

mailnews/base/util/nsMsgIdentity.cpp

@@ -31,7 +31,7 @@
 
 static NS_DEFINE_CID(kPrefServiceCID, NS_PREF_CID);
 
-NS_IMPL_ISUPPORTS1(nsMsgIdentity,
+NS_IMPL_THREADSAFE_ISUPPORTS1(nsMsgIdentity,
                    nsIMsgIdentity)
 
 nsMsgIdentity::nsMsgIdentity():