Cleanup attributes generation in dart:html.

lib/dom/scripts/systemfrog.py

Index: lib/dom/scripts/systemfrog.py
diff --git a/lib/dom/scripts/systemfrog.py b/lib/dom/scripts/systemfrog.py
index 06ca88121d962687b2a4bd81d6662f64becbd24b..9f37a70656041a5582115a43b3444a8ef27998d0 100644
--- a/lib/dom/scripts/systemfrog.py
+++ b/lib/dom/scripts/systemfrog.py
@@ -315,14 +315,14 @@ class FrogInterfaceGenerator(BaseGenerator):
 
 
   def AddSecondaryAttribute(self, interface, attribute):
-    self._SecondaryContext(interface)
+    self.SecondaryContext(interface)
     self.AddAttribute(attribute)
 
   def AddSecondaryOperation(self, interface, info):
-    self._SecondaryContext(interface)
+    self.SecondaryContext(interface)
     self.AddOperation(info)
 
-  def _SecondaryContext(self, interface):
+  def SecondaryContext(self, interface):
     if interface is not self._current_secondary_parent:
       self._current_secondary_parent = interface
       self._members_emitter.Emit('\n  // From $WHERE\n', WHERE=interface.id)