Fixing Solaris bustage for TOOLBAR_DD ifdef.

layout/xul/base/src/nsToolbarFrame.h

@@ -46,6 +46,10 @@
 #include "nsCOMPtr.h"
 #include "nsBoxFrame.h"
 
+#ifdef TOOLBAR_DD
+#include "nsIStyleContext.h"
+#endif
+
 #ifdef TOOLBAR_DD
 class nsToolbarDragListener;
 class nsToolbarMouseMotionListener;