Mojo C++ bindings: extract code shared by different variants.

mojo/public/tools/bindings/generators/cpp_templates/module-shared.h.tmpl

 // 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.
 
 {%- set header_guard = "%s_SHARED_H_"|format(
         module.path|upper|replace("/","_")|replace(".","_")|
             replace("-", "_")) %}
 
 #ifndef {{header_guard}}
 #define {{header_guard}}
 
-// TODO(yzshen): Move code here.
+#include <stdint.h>
+
+#include <functional>
+#include <ostream>
+#include <type_traits>
+#include <utility>
+
+#include "mojo/public/cpp/bindings/enum_traits.h"
+#include "mojo/public/cpp/bindings/lib/serialization_forward.h"
+#include "mojo/public/cpp/bindings/native_enum.h"
+#include "{{module.path}}-shared-internal.h"
+{%- for import in imports %}
+#include "{{import.module.path}}-shared.h"
+{%- endfor %}
+
+{%-   for namespace in namespaces_as_array %}
+namespace {{namespace}} {
+{%-   endfor %}
+
+{#--- Enums #}
+{%- from "enum_macros.tmpl" import enum_decl%}
+{%- for enum in all_enums %}
+{%-   if enum|is_native_only_kind %}
+using {{enum.name}} = mojo::NativeEnum;
+{%-   else %}
+{{enum_decl(enum)}}
+{%-   endif %}
+{%- endfor %}
+
+{%-   for namespace in namespaces_as_array|reverse %}
+}  // namespace {{namespace}}
+{%-   endfor %}
+
+namespace std {
+
+{%- from "enum_macros.tmpl" import enum_hash %}
+{%- for enum in all_enums %}
+{%-   if not enum|is_native_only_kind %}
+{{enum_hash(enum)}}
+{%-   endif %}
+{%- endfor %}
+
+}  // namespace std
+
+namespace mojo {
+
+{#--- Enum Serialization Helpers -#}
+{%- for enum in all_enums %}
+{%-   if not enum|is_native_only_kind %}
+{%      include "enum_serialization_declaration.tmpl" %}
+{%-   endif %}
+{%- endfor %}
+
+}  // namespace mojo
 
 #endif  // {{header_guard}}