Fix build breakage caused by commit 5196.

client/dom/scripts/systemhtml.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 system to generate
 Dart:html APIs from the IDL database."""
 
 from systemfrog import *
 from systeminterface import *
@@ skipping 710 matching lines @@
         PARENTS=', '.join(
             self._shared.GetParentsEventsClasses(self._interface)))
 
     for event_name in event_attrs:
       if event_name in _html_event_names:
         events_members.Emit('\n  EventListenerList get $NAME();\n',
           NAME=_html_event_names[event_name])
       else:
         raise Exception('No known html even name for event: ' + event_name)
 
-  def _EmitEventGetter(self, interface):
+  def _EmitEventGetter(self, events_interface):
     self._members_emitter.Emit('\n  $TYPE get on();\n',
-                               TYPE=interface)
+                               TYPE=events_interface)
 
 # ------------------------------------------------------------------------------
 
 # TODO(jmesserly): inheritance is probably not the right way to factor this long
 # term, but it makes merging better for now.
 class HtmlFrogClassGenerator(FrogInterfaceGenerator):
   """Generates a Frog class for the dart:html library from a DOM IDL
   interface.
   """
 
@@ skipping 48 matching lines @@
     constructor_info = AnalyzeConstructor(interface)
     if constructor_info:
       self._EmitFactoryProvider(interface_name, constructor_info)
 
     emit_events, events = self._shared.GetEventAttributes(self._interface)
     if not emit_events:
       return
     elif events:
       self.AddEventAttributes(events)
     else:
-      self._EmitEventGetter(self._shared.GetParentEventsClass(self._interface))
+      parent_events_class = self._shared.GetParentEventsClass(self._interface)
+      self._EmitEventGetter('_' + parent_events_class + 'Impl')
 
   def _EmitFactoryProvider(self, interface_name, constructor_info):
     template_file = 'factoryprovider_%s.darttemplate' % interface_name
     template = self._system._templates.TryLoad(template_file)
     if not template:
       template = self._system._templates.Load('factoryprovider.darttemplate')
 
     factory_provider = '_' + interface_name + 'FactoryProvider'
     emitter = self._system._ImplFileEmitter(factory_provider)
     emitter.Emit(
@@ skipping 235 matching lines @@
     for event_name in event_attrs:
       if event_name in _html_event_names:
         events_members.Emit(
             "\n"
             "  EventListenerList get $NAME() => _get('$RAWNAME');\n",
             RAWNAME=event_name,
             NAME=_html_event_names[event_name])
       else:
         raise Exception('No known html even name for event: ' + event_name)
 
-  def _EmitEventGetter(self, interface):
+  def _EmitEventGetter(self, events_class):
     self._members_emitter.Emit(
         '\n  $TYPE get on() =>\n    new $TYPE($EVENTTARGET);\n',
-        TYPE=interface,
+        TYPE=events_class,
         EVENTTARGET='_jsDocument' if self._interface.id == 'Document'
             else 'this')
 
 # ------------------------------------------------------------------------------
 
 class HtmlFrogSystem(HtmlSystem):
 
   def __init__(self, templates, database, emitters, output_dir, generator):
     super(HtmlFrogSystem, self).__init__(
         templates, database, emitters, output_dir, generator)
@@ skipping 206 matching lines @@
     constructor_info = AnalyzeConstructor(interface)
     if constructor_info:
       self._EmitFactoryProvider(interface_name, constructor_info)
 
     emit_events, events = self._shared.GetEventAttributes(self._interface)
     if not emit_events:
       return
     elif events:
       self.AddEventAttributes(events)
     else:
-      self._EmitEventGetter(self._shared.GetParentEventsClass(self._interface))
+      parent_events_class = self._shared.GetParentEventsClass(self._interface)
+      self._EmitEventGetter('_' + parent_events_class + 'Impl')
 
   def _EmitFactoryProvider(self, interface_name, constructor_info):
     template_file = 'factoryprovider_%s.darttemplate' % interface_name
     template = self._system._templates.TryLoad(template_file)
     if not template:
       template = self._system._templates.Load('factoryprovider.darttemplate')
 
     factory_provider = '_' + interface_name + 'FactoryProvider'
     emitter = self._system._ImplFileEmitter(factory_provider)
     emitter.Emit(
@@ skipping 465 matching lines @@
     # dispatch has removed f(X), leaving only f(Y), but there is no guarantee
     # that Y = Z-X, so we need to check for Y.
     true_code = emitter.Emit(
         '$(INDENT)if ($COND) {\n'
         '$!TRUE'
         '$(INDENT)}\n',
         COND=test, INDENT=indent)
     self.GenerateDispatch(
         true_code, info, indent + '  ', position + 1, positive)
     return True