Revert "Revert "Fix dart2js type warnings""

tools/dom/scripts/htmldartgenerator.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."""
 
 import emitter
 from generator import AnalyzeOperation, ConstantOutputOrder, \
@@ skipping 93 matching lines @@
       self.AddOperation(info, declare_only)
       if ('%s.%s' % (interface.id, info.declared_name) in
           convert_to_future_members):
         self.AddOperation(ConvertToFuture(info), declare_only)
 
   def AddSecondaryMembers(self, interface):
     # With multiple inheritance, attributes and operations of non-first
     # interfaces need to be added.  Sometimes the attribute or operation is
     # defined in the current interface as well as a parent.  In that case we
     # avoid making a duplicate definition and pray that the signatures match.
+    inherited_attrs = []
+    inherited_ops = []
     secondary_parents = self._database.TransitiveSecondaryParents(interface)
     for parent_interface in sorted(secondary_parents):
       if isinstance(parent_interface, str):
         continue
       for attr in sorted(parent_interface.attributes, ConstantOutputOrder):
-        if not FindMatchingAttribute(interface, attr):
+        if (not FindMatchingAttribute(interface, attr) or
+            attr.id not in inherited_attrs):
           if attr.type.id != 'EventHandler':
             self.SecondaryContext(parent_interface)
             self.AddAttribute(attr)
+            inherited_attrs.append(attr.id)
 
       # Group overloaded operations by name.
       operationsByName =self._OperationsByName(parent_interface)
 
       if self.OmitOperationOverrides():
         self._RemoveShadowingOperationsWithSameSignature(operationsByName,
             interface)
 
       # Generate operations.
       for id in sorted(operationsByName.keys()):
-        if not any(op.id == id for op in interface.operations):
+        if (not any(op.id == id for op in interface.operations)
+            or id not in inherited_ops):
           operations = operationsByName[id]
           info = AnalyzeOperation(interface, operations)
           self.SecondaryContext(parent_interface)
           self.AddOperation(info)
+          inherited_ops.append(id)
 
   def _RemoveShadowingOperationsWithSameSignature(self, operationsByName,
       interface):
     if not interface.parents:
       return
 
     parent = self._database.GetInterface(interface.parents[0].type.id)
     if parent == self._interface or parent == interface:
       return
     for operation in parent.operations:
@@ skipping 553 matching lines @@
 
   def SecureBaseName(self, type_name):
     if type_name in _secure_base_types:
       return _secure_base_types[type_name]
 
   def _DartType(self, type_name):
     return self._type_registry.DartType(type_name)
 
   def _TypeInfo(self, type_name):
     return self._type_registry.TypeInfo(type_name)