Do not treat callbacks with no handlers as interfaces.

lib/dom/scripts/dartgenerator.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 generates Dart APIs from the IDL database."""
 
 import emitter
 import idlnode
 import logging
@@ skipping 205 matching lines @@
           super_database.HasInterface(super_name)):
         interface.ext_attrs['synthesizedSuperInterfaceName'] = super_name
 
       interface_name = interface.id
       auxiliary_file = self._auxiliary_files.get(interface_name)
       if auxiliary_file is not None:
         _logger.info('Skipping %s because %s exists' % (
             interface_name, auxiliary_file))
         continue
 
-      info = RecognizeCallback(interface)
-      if info:
-       system.ProcessCallback(interface, info)
+      if 'Callback' in interface.ext_attrs:
+        handlers = [op for op in interface.operations if op.id == 'handleEvent']
+        if not handlers:
+          # FIXME: fix MutationCallback and assert(handlers).
+          _logger.info('Malformed callback: %s' % interface.id)
+          continue
+        info = AnalyzeOperation(interface, handlers)
+        system.ProcessCallback(interface, info)
       else:
-        if 'Callback' in interface.ext_attrs:
-          _logger.info('Malformed callback: %s' % interface.id)
         _logger.info('Generating %s' % interface.id)
         system.ProcessInterface(interface)
 
     system.GenerateLibraries()
     system.Finish()
 
   def _PreOrderInterfaces(self, interfaces):
     """Returns the interfaces in pre-order, i.e. parents first."""
     seen = set()
     ordered = []
@@ skipping 94 matching lines @@
         PARAMETERS=constructor_info.ParametersImplementationDeclaration(DartType))
 
   def FinishInterface(self):
     pass
 
   def AddTypedArrayConstructors(self, element_type):
     pass
 
   def AddEventAttributes(self, event_attrs):
     pass