goprotobuf: Better enum construction.

R=r
CC=golang-dev
http://codereview.appspot.com/6188053
diff --git a/proto/text_parser_test.go b/proto/text_parser_test.go
index dbd6b2c..f9f09d9 100644
--- a/proto/text_parser_test.go
+++ b/proto/text_parser_test.go
@@ -158,7 +158,7 @@
 		in: `count:42 bikeshed: BLUE`,
 		out: &MyMessage{
 			Count:    Int32(42),
-			Bikeshed: NewMyMessage_Color(MyMessage_BLUE),
+			Bikeshed: MyMessage_BLUE.Enum(),
 		},
 	},