Initial work on Dart bindings for Mojo.

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

+{#--- Begin #}
+
+class {{struct.name}} implements bindings.MojoType<{{struct.name}}> {
+{#--- Enums #}
+{%- from "enum_definition.tmpl" import enum_def %}
+{%  for enum in struct.enums %}
+  {{enum_def("  static ", enum)}}
+{%-  endfor %}
+
+
+{#--- Constants #}
+{%  for constant in struct.constants %}
+  static final {{constant.name}} = {{constant.value|expression_to_text}};
+{%-  endfor %}
+
+
+{#--- initDefaults() #}
+{%- for packed_field in struct.packed.packed_fields %}
+  {{packed_field.field.kind|dart_decl_type}} {{packed_field.field.name}} = {{packed_field.field|default_value}};
+{%- endfor %}
+
+  {{struct.name}}();
+
+{#--- Encoding and decoding #}
+
+  static const int encodedSize =
+      bindings.kStructHeaderSize + {{struct.packed|payload_size}};
+
+  static {{struct.name}} decode(bindings.MojoDecoder decoder) {
+    var packed;
+    var val = new {{struct.name}}();
+    var numberOfBytes = decoder.readUint32();
+    var numberOfFields = decoder.readUint32();
+{%- for byte in struct.bytes %}
+{%-   if byte.packed_fields|length > 1 %}
+    packed = decoder.readUint8();
+{%-     for packed_field in byte.packed_fields %}
+    val.{{packed_field.field.name}} = (((packed >> {{packed_field.bit}}) & 1) != 0) ? true : false;
+{%-     endfor %}
+{%-   else %}
+{%-     for packed_field in byte.packed_fields %}
+    val.{{packed_field.field.name}} = decoder.{{packed_field.field.kind|decode_snippet}};
+{%-     endfor %}
+{%-   endif %}
+{%-   if byte.is_padding %}
+    decoder.skip(1);
+{%-   endif %}
+{%- endfor %}
+    return val;
+  }
+
+  static void encode(bindings.MojoEncoder encoder, {{struct.name}} val) {
+    var packed;
+    encoder.writeUint32({{struct.name}}.encodedSize);
+    encoder.writeUint32({{struct.packed.packed_fields|length}});
+
+{%- for byte in struct.bytes %}
+{%-   if byte.packed_fields|length > 1 %}
+    packed = 0;
+{%-     for packed_field in byte.packed_fields %}
+    packed |= (val.{{packed_field.field.name}} & 1) << {{packed_field.bit}}
+{%-     endfor %}
+    encoder.writeUint8(packed);
+{%-   else %}
+{%-     for packed_field in byte.packed_fields %}
+    encoder.{{packed_field.field.kind|encode_snippet}}val.{{packed_field.field.name}});
+{%-     endfor %}
+{%-   endif %}
+{%-   if byte.is_padding %}
+    encoder.skip(1);
+{%-   endif %}
+{%- endfor %}
+  }
+}