Backed out changeset dc265cc31095 (bug 1091900)

js/src/jsiter.cpp

@@ -666,8 +666,11 @@ js::GetIterator(JSContext *cx, HandleObject obj, unsigned flags, MutableHandleVa
     bool keysOnly = (flags == JSITER_ENUMERATE);
 
     if (obj) {
-        if (obj->is<PropertyIteratorObject>() || obj->is<LegacyGeneratorObject>()) {
-            vp.setObject(*obj);
+        if (JSIteratorOp op = obj->getClass()->ext.iteratorObject) {
+            JSObject *iterobj = op(cx, obj, !(flags & JSITER_FOREACH));
+            if (!iterobj)
+                return false;
+            vp.setObject(*iterobj);
             return true;
         }
 
@@ -888,6 +891,12 @@ static const JSFunctionSpec iterator_methods[] = {
     JS_FS_END
 };
 
+static JSObject *
+iterator_iteratorObject(JSContext *cx, HandleObject obj, bool keysonly)
+{
+    return obj;
+}
+
 size_t
 PropertyIteratorObject::sizeOfMisc(mozilla::MallocSizeOf mallocSizeOf) const
 {
@@ -926,6 +935,12 @@ const Class PropertyIteratorObject::class_ = {
     nullptr,                 /* hasInstance */
     nullptr,                 /* construct   */
     trace,
+    JS_NULL_CLASS_SPEC,
+    {
+        nullptr,             /* outerObject    */
+        nullptr,             /* innerObject    */
+        iterator_iteratorObject,
+    }
 };
 
 enum {