fix warnings

layout/xul/base/src/nsBoxFrame.cpp

@@ -124,7 +124,7 @@ class nsInfoListImpl: public nsInfoList
 {
 public:
     nsInfoListImpl();
-    ~nsInfoListImpl();
+    virtual ~nsInfoListImpl();
     virtual nsCalculatedBoxInfo* GetFirst();
     virtual nsCalculatedBoxInfo* GetLast();
     virtual nsCalculatedBoxInfo* GetFirstCreateIfNeeded();

xpcom/base/nsIInterfaceRequestor.idl

@@ -65,6 +65,7 @@ class NS_EXPORT nsGetInterface : public nsCOMPtr_helper
         }
 
       virtual nsresult operator()( const nsIID&, void** ) const;
+      virtual ~nsGetInterface() {};
 
     private:
       nsCOMPtr<nsISupports> mSource;
@@ -78,4 +79,5 @@ do_GetInterface( nsISupports* aSource, nsresult* error = 0 )
     return nsGetInterface(aSource, error);
   }
 
-%}
+%}
+