Fix bug with using enums as default values in mojom. We were previously

mojo/public/bindings/generators/mojom_cpp_generator.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates C++ source files from a mojom.Module."""
 
 from generate import mojom
 from generate import mojom_pack
 from generate import mojom_generator
 
@@ skipping 84 matching lines @@
   if kind.spec == 's':
     return "mojo::internal::StringPointer"
   return _kind_to_cpp_type[kind]
 
 def IsStructWithHandles(struct):
   for pf in struct.packed.packed_fields:
     if mojom_generator.IsHandleKind(pf.field.kind):
       return True
   return False
 
-def SubstituteNamespace(value, imports):
-  for import_item in imports:
-    value = value.replace(import_item['namespace'] + ".",
-        import_item['namespace'] + "::")
-  return value
+def SubstituteNamespace(token, module):
+  for import_item in module.imports:
+    token = token.replace(import_item["namespace"] + ".",
+        import_item["namespace"] + "::")
+  return token
+
+def ExpressionToText(value, module):
+  if value[0] != "EXPRESSION":
+    raise Exception("Expected EXPRESSION, got" + value)
+  return "".join(mojom_generator.ExpressionMapper(value,
+      lambda token: SubstituteNamespace(token, module)))
 
 _HEADER_SIZE = 8
 
 class Generator(mojom_generator.Generator):
 
   cpp_filters = {
     "camel_to_underscores": mojom_generator.CamelToUnderscores,
     "cpp_const_wrapper_type": GetCppConstWrapperType,
     "cpp_field_type": GetCppFieldType,
     "cpp_type": GetCppType,
     "cpp_wrapper_type": GetCppWrapperType,
+    "expression_to_text": ExpressionToText,
     "get_pad": mojom_pack.GetPad,
     "is_handle_kind": mojom_generator.IsHandleKind,
     "is_object_kind": mojom_generator.IsObjectKind,
     "is_string_kind": mojom_generator.IsStringKind,
     "is_array_kind": lambda kind: isinstance(kind, mojom.Array),
     "is_struct_with_handles": IsStructWithHandles,
     "struct_size": lambda ps: ps.GetTotalSize() + _HEADER_SIZE,
     "struct_from_method": mojom_generator.GetStructFromMethod,
     "stylize_method": mojom_generator.StudlyCapsToCamel,
-    "substitute_namespace": SubstituteNamespace,
     "verify_token_type": mojom_generator.VerifyTokenType,
   }
 
   def GetJinjaExports(self):
     return {
+      "module": self.module,
       "module_name": self.module.name,
       "namespace": self.module.namespace,
       "imports": self.module.imports,
       "kinds": self.module.kinds,
       "enums": self.module.enums,
       "structs": self.GetStructs(),
       "interfaces": self.module.interfaces,
       "include_prefix": self.GetIncludePrefix(),
     }
 
@@ skipping 14 matching lines @@
     self.Write(self.GenerateModuleInternalHeader(),
         "%s_internal.h" % self.module.name)
     self.Write(self.GenerateModuleSource(), "%s.cc" % self.module.name)
 
   def GetIncludePrefix(self):
     if not self.header_dir:
       return ""
     if self.header_dir[-1] == "/":
       return self.header_dir
     return self.header_dir + "/"