Revert "Revert "Start of dartium custom element lifecycle event support.""

tools/dom/scripts/systemnative.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """This module provides shared functionality for the systems to generate
 native binding from the IDL database."""
 
 import emitter
 import os
@@ skipping 771 matching lines @@
       cpp_arguments = ['document']
 
     if 'ImplementedBy' in ext_attrs:
       assert needs_receiver
       self._cpp_impl_includes.add('"%s.h"' % ext_attrs['ImplementedBy'])
       cpp_arguments.append('receiver')
 
     if 'Reflect' in ext_attrs:
       cpp_arguments = [self._GenerateWebCoreReflectionAttributeName(node)]
 
-    if return_type_is_nullable:
-      cpp_arguments = ['isNull']
-
     if ext_attrs.get('CustomElementCallbacks') == 'Enable':
       self._cpp_impl_includes.add('"core/dom/CustomElementCallbackDispatcher.h"')
       needs_custom_element_callbacks = True
 
+    if return_type_is_nullable:
+      cpp_arguments = ['isNull']
+
     v8EnabledPerContext = ext_attrs.get('synthesizedV8EnabledPerContext', ext_attrs.get('V8EnabledPerContext'))
     v8EnabledAtRuntime = ext_attrs.get('synthesizedV8EnabledAtRuntime', ext_attrs.get('V8EnabledAtRuntime'))
     assert(not (v8EnabledPerContext and v8EnabledAtRuntime))
 
     if v8EnabledPerContext:
       raises_exceptions = True
       self._cpp_impl_includes.add('"ContextFeatures.h"')
       self._cpp_impl_includes.add('"DOMWindow.h"')
       runtime_check = emitter.Format(
           '        if (!ContextFeatures::$(FEATURE)Enabled(DartUtilities::domWindowForCurrentIsolate()->document())) {\n'
@@ skipping 370 matching lines @@
             '    if (Dart_NativeFunction func = $CLASS_NAME::resolver(name, argumentCount))\n'
             '        return func;\n',
             CLASS_NAME=os.path.splitext(os.path.basename(path))[0])
 
 def _IsOptionalStringArgumentInInitEventMethod(interface, operation, argument):
   return (
       interface.id.endswith('Event') and
       operation.id.startswith('init') and
       argument.ext_attrs.get('Default') == 'Undefined' and
       argument.type.id == 'DOMString')