Bug 1391803 - Use nsStringFwd.h for forward declaring string classes. r=froydnj

We should not be declaring forward declarations for nsString classes directly,
instead we should use nsStringFwd.h. This will make changing the underlying
types easier.

parser/html/nsHtml5ArrayCopy.h

@@ -23,8 +23,8 @@
 #ifndef nsHtml5ArrayCopy_h
 #define nsHtml5ArrayCopy_h
 
+#include "nsStringFwd.h"
 
-class nsString;
 class nsHtml5StackNode;
 class nsHtml5AttributeName;