Mojom runtime type info: New implementation for Dart.

mojo/public/tools/bindings/generators/dart_templates/struct_definition.tmpl

 {#--- Begin #}
 {%- import "encoding_macros.tmpl" as encoding_macros %}
-{%- import "mojom_type_macros.tmpl" as mojom_type_macros %}
 {%- macro struct_def(struct, typepkg, package) %}
 {#--- Enums #}
 {%- from "enum_definition.tmpl" import enum_def %}
 {%-  for enum in struct.enums %}
 {{enum_def(enum, typepkg, package)}}
 {%-  endfor %}
 
 class {{struct|name}} extends bindings.Struct {
   static const List<bindings.StructDataHeader> kVersions = const [
 {%- for version in struct.versions %}
@@ skipping 90 matching lines @@
     map["{{packed_field.field|name}}"] = {{packed_field.field|name}};
     {%- endfor %}
     return map;
     {%- else %}
     throw new bindings.MojoCodecError(
         'Object containing handles cannot be encoded to JSON.');
     {%- endif %}
   }
 }
 
-{% if should_gen_mojom_types -%}
-{{ mojom_type_macros.writeMojomTypeDef(struct, typepkg, package) }}
-{%- endif -%}
 {%- endmacro %}