Allow constants as field initial values as well as creation thunks

lib/src/protobuf/builder_info.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of protobuf;
 
 /**
  * Per-message type setup.
  */
 class BuilderInfo {
   final String messageName;
   final Map<int, FieldInfo> fieldInfo = new Map<int, FieldInfo>();
   final Map<String, FieldInfo> byName = <String, FieldInfo>{};
   bool hasExtensions = false;
   bool hasRequiredFields = true;
 
   BuilderInfo(this.messageName);
 
   void add(int tagNumber, String name, int fieldType,
-           MakeDefaultFunc makeDefault,
+           dynamic defaultOrMaker,
            CreateBuilderFunc subBuilder,
            ValueOfFunc valueOf) {
     fieldInfo[tagNumber] = byName[name] = new FieldInfo(
-      name, tagNumber, fieldType, makeDefault, subBuilder, valueOf);
+      name, tagNumber, fieldType, defaultOrMaker, subBuilder, valueOf);
   }
 
   void a(int tagNumber, String name, int fieldType,
-         [MakeDefaultFunc makeDefault,
-         CreateBuilderFunc subBuilder,
-         ValueOfFunc valueOf]) {
+         [dynamic defaultOrMaker,
+          CreateBuilderFunc subBuilder,
+          ValueOfFunc valueOf]) {
     add(tagNumber, name, fieldType,
-        makeDefault, subBuilder, valueOf);
+        defaultOrMaker, subBuilder, valueOf);
   }
 
   // Enum.
   void e(int tagNumber, String name, int fieldType,
-         MakeDefaultFunc makeDefault, ValueOfFunc valueOf) {
+         dynamic defaultOrMaker, ValueOfFunc valueOf) {
     add(tagNumber, name, fieldType,
-        makeDefault, null, valueOf);
+        defaultOrMaker, null, valueOf);
   }
 
   // Repeated message.
   // TODO(antonm): change the order of CreateBuilderFunc and MakeDefaultFunc.
   void m(int tagNumber, String name,
          CreateBuilderFunc subBuilder, MakeDefaultFunc makeDefault) {
     add(tagNumber, name, GeneratedMessage._REPEATED_MESSAGE,
         makeDefault, subBuilder, null);
   }
 
@@ skipping 174 matching lines @@
       } else if((fieldType & GeneratedMessage._REQUIRED_BIT) != 0) {
         // Required 'primitive' must be present.
         if (fieldValues[tagNumber] == null) {
           invalidFields.add('${prefix}${field.name}');
         }
       }
     });
     return invalidFields;
   }
 }