well, now it needs to include nsCOMPtr, since the header doesn't anymore

xpcom/base/nsWeakReference.cpp

@@ -1,6 +1,7 @@
 // nsWeakReference.cpp
 
 #include "nsWeakReference.h"
+#include "nsCOMPtr.h"
 
 nsIWeakReference*
 NS_GetWeakReference( nsISupports* aInstance, nsresult* aResult )

xpcom/glue/nsWeakReference.cpp

@@ -1,6 +1,7 @@
 // nsWeakReference.cpp
 
 #include "nsWeakReference.h"
+#include "nsCOMPtr.h"
 
 nsIWeakReference*
 NS_GetWeakReference( nsISupports* aInstance, nsresult* aResult )