Support DateTime conversions.

tools/dom/scripts/generator.py

Index: tools/dom/scripts/generator.py
diff --git a/tools/dom/scripts/generator.py b/tools/dom/scripts/generator.py
index 1a9ee7fff5c15cd580107557de828dec1c202b00..f1a5fa058acc27d390e7e75d47a3b2c3a9e4b599 100644
--- a/tools/dom/scripts/generator.py
+++ b/tools/dom/scripts/generator.py
@@ -1211,7 +1211,10 @@ class PrimitiveIDLTypeInfo(IDLTypeInfo):
       type = 'RefPtr<%s>' % type
     if type == 'String':
       type = 'DartStringAdapter'
-    return '%s', type, 'DartUtilities', 'dartTo%s' % self._capitalized_native_type()
+    target_type = self._capitalized_native_type()
+    if self.idl_type() == 'Date':
+      target_type = 'Date'
+    return '%s', type, 'DartUtilities', 'dartTo%s' % target_type
 
   def parameter_type(self):
     if self.native_type() == 'String':
@@ -1222,8 +1225,14 @@ class PrimitiveIDLTypeInfo(IDLTypeInfo):
     return []
 
   def to_dart_conversion(self, value, interface_name=None, attributes=None):
-    function_name = self._capitalized_native_type()
-    function_name = function_name[0].lower() + function_name[1:]
+    # TODO(antonm): if there are more instances of the case
+    # when conversion depends on both Dart type and C++ type,
+    # consider introducing a corresponding argument/class.
+    if self.idl_type() == 'Date':
+      function_name = 'date'
+    else:
+      function_name = self._capitalized_native_type()
+      function_name = function_name[0].lower() + function_name[1:]
     function_name = 'DartUtilities::%sToDart' % function_name
     if attributes and 'TreatReturnedNullStringAs' in attributes:
       function_name += 'WithNullCheck'
@@ -1332,7 +1341,7 @@ _idl_type_registry = monitored.Dict('generator._idl_type_registry', {
     'any': TypeData(clazz='Primitive', dart_type='Object', native_type='ScriptValue'),
     'Array': TypeData(clazz='Primitive', dart_type='List'),
     'custom': TypeData(clazz='Primitive', dart_type='dynamic'),
-    'Date': TypeData(clazz='Primitive', dart_type='Date', native_type='double'),
+    'Date': TypeData(clazz='Primitive', dart_type='DateTime', native_type='double'),
     'DOMObject': TypeData(clazz='Primitive', dart_type='Object', native_type='ScriptValue'),
     'DOMString': TypeData(clazz='Primitive', dart_type='String', native_type='String'),
     # TODO(vsm): This won't actually work until we convert the Map to