Attempting to fix os/2 and worms bustage. Add a protected default ctor to nsStyleContext. This should never be called since we never instantiate an nsDerivedSafe. r=bbaetz.

content/shared/public/nsStyleContext.h

@@ -113,6 +113,10 @@ public:
 #endif
 
 protected:
+  // A default ctor is needed to use nsRefPtr (nsDerivedSafe) with this class.
+  // It should never be called.
+  nsStyleContext() { NS_NOTREACHED("nsStyleContext default ctor"); }
+
   void AppendChild(nsStyleContext* aChild);
   void RemoveChild(nsStyleContext* aChild);
 

layout/style/nsStyleContext.h

@@ -113,6 +113,10 @@ public:
 #endif
 
 protected:
+  // A default ctor is needed to use nsRefPtr (nsDerivedSafe) with this class.
+  // It should never be called.
+  nsStyleContext() { NS_NOTREACHED("nsStyleContext default ctor"); }
+
   void AppendChild(nsStyleContext* aChild);
   void RemoveChild(nsStyleContext* aChild);