Bug 1196378 - Fix mismatched js_new/js_free in ShellPrincipals, r=fitzgen

--HG--
extra : rebase_source : 25da2c1181e1867ba94da07ac81e5a65a27cd978

js/src/shell/js.cpp

@@ -227,7 +227,7 @@ class ShellPrincipals: public JSPrincipals {
     static void destroy(JSPrincipals* principals) {
         MOZ_ASSERT(principals != &fullyTrusted);
         MOZ_ASSERT(principals->refcount == 0);
-        js_free(static_cast<ShellPrincipals*>(principals));
+        js_delete(static_cast<const ShellPrincipals*>(principals));
     }
 
     static bool subsumes(JSPrincipals* first, JSPrincipals* second) {