Revert "Generate some of the C++ bindings for mojom tagged unions."

mojo/public/tools/bindings/pylib/mojom/parse/translate.py

Index: mojo/public/tools/bindings/pylib/mojom/parse/translate.py
diff --git a/mojo/public/tools/bindings/pylib/mojom/parse/translate.py b/mojo/public/tools/bindings/pylib/mojom/parse/translate.py
index aa34125276178777ae21bf17880e6ffa3646e8ac..88bd2698ade8e5a1e06e7f654187f877bef1a9c3 100644
--- a/mojo/public/tools/bindings/pylib/mojom/parse/translate.py
+++ b/mojo/public/tools/bindings/pylib/mojom/parse/translate.py
@@ -152,7 +152,7 @@ class _MojomBuilder(object):
         _AttributeListToDict(tree.module.attribute_list) if tree.module else {}
     self.mojom['structs'] = \
         _MapTreeForType(StructToDict, tree.definition_list, ast.Struct)
-    self.mojom['unions'] = \
+    self.mojom['union'] = \
         _MapTreeForType(UnionToDict, tree.definition_list, ast.Union)
     self.mojom['interfaces'] = \
         _MapTreeForType(InterfaceToDict, tree.definition_list, ast.Interface)