A few API changes:

tools/dom/scripts/systemnative.py

Index: tools/dom/scripts/systemnative.py
diff --git a/tools/dom/scripts/systemnative.py b/tools/dom/scripts/systemnative.py
index a1b6ee03244ccd33c2fefb77349404071f26e0e7..036d8c7641f9aa3a6b150613d9ab6b0a01a9d19a 100644
--- a/tools/dom/scripts/systemnative.py
+++ b/tools/dom/scripts/systemnative.py
@@ -1204,6 +1204,8 @@ class CPPLibraryEmitter():
     e.Emit('    _LocationCrossFrameClassId,\n');
     e.Emit('    _DOMWindowCrossFrameClassId,\n');
     e.Emit('    _DateTimeClassId,\n');
+    e.Emit('    _JsObjectClassId,\n');
+    e.Emit('    _JsFunctionClassId,\n');
     e.Emit('    // New types that are not auto-generated should be added here.\n');
     e.Emit('\n');
     for interface in database.GetInterfaces():
@@ -1247,6 +1249,8 @@ class CPPLibraryEmitter():
     e.Emit('    { "_LocationCrossFrame", DartHtmlLibraryId, -1, false, false, false },\n');
     e.Emit('    { "_DOMWindowCrossFrame", DartHtmlLibraryId, -1, false, false, true },\n');
     e.Emit('    { "DateTime", DartCoreLibraryId, -1, false, false, false },\n');
+    e.Emit('    { "JsObject", DartJsLibraryId, -1, false, false, false },\n');
+    e.Emit('    { "JsFunction", DartJsLibraryId, _JsObjectClassId, false, false, false },\n');
     e.Emit('    // New types that are not auto-generated should be added here.\n');
     e.Emit('\n');
     is_node_test = lambda interface: interface.id == 'Node'