Future-ify all the html methods and add named parameters

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 06e27a9b5abeed122db7f3b2ece1fd2d358b459d..c15fbb3d0babc18a0f1ab99c963d7d1a643a1c9b 100644
--- a/tools/dom/scripts/systemnative.py
+++ b/tools/dom/scripts/systemnative.py
@@ -10,7 +10,7 @@ import emitter
 import os
 from generator import *
 from htmldartgenerator import *
-from systemhtml import js_support_checks
+from systemhtml import js_support_checks, GetCallbackInfo
 
 class DartiumBackend(HtmlDartGenerator):
   """Generates Dart implementation for one DOM IDL interface."""
@@ -476,12 +476,15 @@ class DartiumBackend(HtmlDartGenerator):
     needs_dispatcher = not is_custom and (len(info.operations) > 1 or has_optional_arguments)
 
     if not needs_dispatcher:
-      # Bind directly to native implementation
-      argument_count = (0 if info.IsStatic() else 1) + len(info.param_infos)
-      cpp_callback_name = self._GenerateNativeBinding(
-          info.name, argument_count, dart_declaration, 'Callback', is_custom)
-      if not is_custom:
-        self._GenerateOperationNativeCallback(operation, operation.arguments, cpp_callback_name)
+      if info.callback_args:
+        self._AddFutureifiedOperation(info, html_name)
+      else:
+        # Bind directly to native implementation
+        argument_count = (0 if info.IsStatic() else 1) + len(info.param_infos)
+        cpp_callback_name = self._GenerateNativeBinding(
+            info.name, argument_count, dart_declaration, 'Callback', is_custom)
+        if not is_custom:
+          self._GenerateOperationNativeCallback(operation, operation.arguments, cpp_callback_name)
     else:
       self._GenerateDispatcher(info.operations, dart_declaration, [info.name for info in info.param_infos])