Mojo cpp bindings: add support for validating incoming messages.

mojo/public/tools/bindings/mojom.gni

 # Copyright 2014 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.
 
 # Generate C++ and JavaScript source files from mojom files.
 template("mojom") {
   assert(defined(invoker.sources),
          "\"sources\" must be defined for the $target_name template.")
 
   generator_root = "//mojo/public/tools/bindings"
   generator_script = "$generator_root/mojom_bindings_generator.py"
   generator_sources = [
     generator_script,
     "$generator_root/generators/cpp_templates/enum_declaration.tmpl",
     "$generator_root/generators/cpp_templates/enum_traits.tmpl",
     "$generator_root/generators/cpp_templates/interface_declaration.tmpl",
     "$generator_root/generators/cpp_templates/interface_definition.tmpl",
     "$generator_root/generators/cpp_templates/interface_macros.tmpl",
     "$generator_root/generators/cpp_templates/interface_proxy_declaration.tmpl",
+    "$generator_root/generators/cpp_templates/interface_request_validator_declaration.tmpl",
+    "$generator_root/generators/cpp_templates/interface_response_validator_declaration.tmpl",
     "$generator_root/generators/cpp_templates/interface_stub_declaration.tmpl",
     "$generator_root/generators/cpp_templates/module.cc.tmpl",
     "$generator_root/generators/cpp_templates/module.h.tmpl",
     "$generator_root/generators/cpp_templates/module-internal.h.tmpl",
     "$generator_root/generators/cpp_templates/params_definition.tmpl",
     "$generator_root/generators/cpp_templates/struct_builder_definition.tmpl",
     "$generator_root/generators/cpp_templates/struct_declaration.tmpl",
     "$generator_root/generators/cpp_templates/struct_definition.tmpl",
     "$generator_root/generators/cpp_templates/struct_destructor.tmpl",
     "$generator_root/generators/cpp_templates/struct_macros.tmpl",
@@ skipping 49 matching lines @@
     hard_dep = true
     sources = process_file_template(invoker.sources, generator_cpp_outputs)
     data = process_file_template(invoker.sources, generator_js_outputs)
     deps = [
       ":$generator_target_name",
       "//mojo/public/cpp/bindings",
     ]
   }
 }