C++ bindings: separate out serialization source set, have "mojom" targets optionally use serializat…

mojo/public/tools/bindings/generators/cpp_templates/module.cc.tmpl

 // 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.
 
 #if defined(__clang__)
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-private-field"
 #elif defined(_MSC_VER)
 #pragma warning(push)
 #pragma warning(disable:4056)
 #pragma warning(disable:4065)
 #pragma warning(disable:4756)
 #endif
 
 #include "{{module.path}}.h"
 
 #include <math.h>
 #include <ostream>
 
 #include "mojo/public/cpp/bindings/lib/array_serialization.h"
 #include "mojo/public/cpp/bindings/lib/bindings_serialization.h"
 #include "mojo/public/cpp/bindings/lib/bounds_checker.h"
 #include "mojo/public/cpp/bindings/lib/map_data_internal.h"
 #include "mojo/public/cpp/bindings/lib/map_serialization.h"
 #include "mojo/public/cpp/bindings/lib/message_builder.h"
+#include "mojo/public/cpp/bindings/lib/message_validation.h"
 #include "mojo/public/cpp/bindings/lib/string_serialization.h"
 #include "mojo/public/cpp/bindings/lib/validate_params.h"
 #include "mojo/public/cpp/bindings/lib/validation_errors.h"
 #include "mojo/public/cpp/bindings/lib/validation_util.h"
 #include "mojo/public/cpp/environment/lib/scoped_task_tracking.h"
 #include "mojo/public/cpp/environment/logging.h"
 #include "mojo/public/interfaces/bindings/interface_control_messages.mojom.h"
 
 {%- for namespace in namespaces_as_array %}
 namespace {{namespace}} {
@@ skipping 89 matching lines @@
 
 {%- for namespace in namespaces_as_array|reverse %}
 }  // namespace {{namespace}}
 {%- endfor %}
 
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #elif defined(_MSC_VER)
 #pragma warning(pop)
 #endif