Initial work on Dart bindings for Mojo.

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

Index: mojo/public/tools/bindings/generators/dart_templates/enum_definition.tmpl
diff --git a/mojo/public/tools/bindings/generators/dart_templates/enum_definition.tmpl b/mojo/public/tools/bindings/generators/dart_templates/enum_definition.tmpl
new file mode 100644
index 0000000000000000000000000000000000000000..ad5f3408d78d3ae284a1dd7cbe65fd35f06afc41
--- /dev/null
+++ b/mojo/public/tools/bindings/generators/dart_templates/enum_definition.tmpl
@@ -0,0 +1,12 @@
+{%- macro enum_def(prefix, enum) -%}
+{%- set prev_enum = 0 %}
+{%- for field in enum.fields %}
+{%-   if field.value %}
+{{prefix}}const int {{enum.name}}_{{field.name}} = {{field.value|expression_to_text}};
+{%-   elif loop.first %}
+{{prefix}}const int {{enum.name}}_{{field.name}} = 0;
+{%-   else %}
+{{prefix}}const int {{enum.name}}_{{field.name}} = {{enum.fields[loop.index0 - 1].name}} + 1;
+{%-   endif %}
+{%- endfor %}
+{%- endmacro %}