Followup for bug 510651 to make non-debug builds with --enable-extensions=layout-debug build.

extensions/layout-debug/src/nsLayoutDebuggingTools.cpp

@@ -428,6 +428,7 @@ nsLayoutDebuggingTools::DumpContent()
 static void
 DumpFramesRecur(nsIDocShell* aDocShell, FILE* out)
 {
+#ifdef DEBUG
     fprintf(out, "webshell=%p \n", static_cast<void*>(aDocShell));
     nsCOMPtr<nsIPresShell> shell(pres_shell(aDocShell));
     if (shell) {
@@ -452,6 +453,7 @@ DumpFramesRecur(nsIDocShell* aDocShell, FILE* out)
             DumpFramesRecur(childAsShell, out);
         }
     }
+#endif
 }
 
 NS_IMETHODIMP