Roll 50: Updated for push to origin/master.

tools/dom/scripts/htmldartgenerator.py

Index: tools/dom/scripts/htmldartgenerator.py
diff --git a/tools/dom/scripts/htmldartgenerator.py b/tools/dom/scripts/htmldartgenerator.py
index 62056e7372a046fda358ba223c8aad680b8e6b09..53be964e59dea1aabe6ff74ca98d441f7afce4a8 100644
--- a/tools/dom/scripts/htmldartgenerator.py
+++ b/tools/dom/scripts/htmldartgenerator.py
@@ -393,11 +393,13 @@ class HtmlDartGenerator(object):
       generate_call(stmts_emitter, call_emitter,
           version[0], signature_index, argument_count)
 
+    def IsTypeChecking(interface_argument):
+      return 'LegacyInterfaceTypeChecking' in interface_argument.ext_attrs or \
+      self._database.HasInterface(interface_argument.id)
+
     def GenerateChecksAndCall(signature_index, argument_count):
       checks = []
-      typechecked_interface = \
-          ('TypeChecking' in self._interface.ext_attrs) and \
-          ('Interface' in self._interface.ext_attrs['TypeChecking'])
+      typechecked_interface = IsTypeChecking(self._interface)
 
       for i in reversed(range(0, argument_count)):
         argument = signatures[signature_index][i]
@@ -408,9 +410,7 @@ class HtmlDartGenerator(object):
         if test_type in ['dynamic', 'Object']:
           checks.append('%s != null' % parameter_name)
         elif not can_omit_type_check(test_type, i):
-          typechecked = typechecked_interface or \
-              ('TypeChecking' in argument.ext_attrs) and \
-              ('Interface' in argument.ext_attrs['TypeChecking'])
+          typechecked = typechecked_interface or IsTypeChecking(argument)
           converts_null = \
               ('TreatNullAs' in argument.ext_attrs) or \
               (argument.default_value is not None) or \
@@ -541,9 +541,10 @@ class HtmlDartGenerator(object):
 
   def _AddConstructor(self,
       constructor_info, factory_name, factory_constructor_name):
-    # Hack to ignore the Image constructor used by JavaScript.
+    # Hack to ignore the constructor used by JavaScript.
     if ((self._interface.id == 'HTMLImageElement' or
          self._interface.id == 'Blob' or
+         self._interface.id == 'TouchEvent' or
          self._interface.id == 'DOMException')
       and not constructor_info.pure_dart_constructor):
       return