Mojo: Report bindings validation errors via MojoNotifyBadMessage

mojo/public/cpp/bindings/lib/native_enum_data.h

 // Copyright 2016 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_NATIVE_ENUM_DATA_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_NATIVE_ENUM_DATA_H_
 
 namespace mojo {
 namespace internal {
 
+class ValidationContext;
+
 class NativeEnum_Data {
  public:
   static bool const kIsExtensible = true;
 
   static bool IsKnownValue(int32_t value) { return false; }
 
-  static bool Validate(int32_t value) { return true; }
+  static bool Validate(int32_t value,
+                       ValidationContext* validation_context) { return true; }
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_NATIVE_ENUM_DATA_H_