Mojo C++ bindings: share DataView class between chromium and blink variants.

mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_declaration.tmpl

 {%- import "struct_macros.tmpl" as struct_macros %}
-{%- set mojom_type = struct|get_qualified_name_for_kind %}
+{%- set data_view = struct|get_qualified_name_for_kind ~ "DataView" %}
 {%- set data_type = struct|get_qualified_name_for_kind(internal=True) %}
 
-template <>
-struct {{export_attribute}} StructTraits<{{mojom_type}}::DataView, {{mojom_type}}Ptr> {
-  static bool IsNull(const {{mojom_type}}Ptr& input) { return !input; }
-  static void SetToNull({{mojom_type}}Ptr* output) { output->reset(); }
-
-{%- for field in struct.fields %}
-{%-   set return_ref = field.kind|is_object_kind or
-                       field.kind|is_any_handle_or_interface_kind %}
-{%-   if return_ref %}
-  static decltype({{mojom_type}}::{{field.name}})& {{field.name}}(
-      {{mojom_type}}Ptr& input) {
-    return input->{{field.name}};
-  }
-{%-   else %}
-  static decltype({{mojom_type}}::{{field.name}}) {{field.name}}(
-      const {{mojom_type}}Ptr& input) {
-    return input->{{field.name}};
-  }
-{%-   endif %}
-{%- endfor %}
-
-  static bool Read({{mojom_type}}::DataView input, {{mojom_type}}Ptr* output);
-};
-
 namespace internal {
 
 template <typename MaybeConstUserType>
-struct Serializer<{{mojom_type}}Ptr, MaybeConstUserType> {
+struct Serializer<{{data_view}}, MaybeConstUserType> {
   using UserType = typename std::remove_const<MaybeConstUserType>::type;
-  using Traits = StructTraits<{{mojom_type}}::DataView, UserType>;
+  using Traits = StructTraits<{{data_view}}, UserType>;
 
   static size_t PrepareToSerialize(MaybeConstUserType& input,
                                    SerializationContext* context) {
     if (CallIsNullIfExists<Traits>(input))
       return 0;
 
     void* custom_context = CustomContextHelper<Traits>::SetUp(input, context);
     ALLOW_UNUSED_LOCAL(custom_context);
 
     {{struct_macros.get_serialized_size(
@@ skipping 21 matching lines @@
 
     CustomContextHelper<Traits>::TearDown(input, custom_context);
   }
 
   static bool Deserialize({{data_type}}* input,
                           UserType* output,
                           SerializationContext* context) {
     if (!input)
       return CallSetToNullIfExists<Traits>(output);
 
-    {{mojom_type}}::DataView data_view(input, context);
+    {{data_view}} data_view(input, context);
     return Traits::Read(data_view, output);
   }
 };
 
 }  // namespace internal