veyron/security/serialization: name unnamed array type

Change-Id: Idebc1f3e5b3fb16a53934084bc19b5d82273ebab
diff --git a/security/serialization/types.vdl b/security/serialization/types.vdl
index 2033af3..e185799 100644
--- a/security/serialization/types.vdl
+++ b/security/serialization/types.vdl
@@ -6,8 +6,10 @@
   ChunkSizeBytes int64
 }
 
+type HashCode [32]byte
+
 // SignedData describes the information sent by a SigningWriter and read by VerifiyingReader.
 type SignedData union {
 	Signature security.Signature
-	Hash [32]byte
-}
\ No newline at end of file
+	Hash HashCode
+}
diff --git a/security/serialization/types.vdl.go b/security/serialization/types.vdl.go
index f73ef5c..daa5cac 100644
--- a/security/serialization/types.vdl.go
+++ b/security/serialization/types.vdl.go
@@ -19,6 +19,13 @@
 }) {
 }
 
+type HashCode [32]byte
+
+func (HashCode) __VDLReflect(struct {
+	Name string "v.io/core/veyron/security/serialization.HashCode"
+}) {
+}
+
 type (
 	// SignedData represents any single field of the SignedData union type.
 	//
@@ -36,7 +43,7 @@
 	// SignedDataSignature represents field Signature of the SignedData union type.
 	SignedDataSignature struct{ Value security.Signature }
 	// SignedDataHash represents field Hash of the SignedData union type.
-	SignedDataHash struct{ Value [32]byte }
+	SignedDataHash struct{ Value HashCode }
 	// __SignedDataReflect describes the SignedData union type.
 	__SignedDataReflect struct {
 		Name  string "v.io/core/veyron/security/serialization.SignedData"
@@ -60,5 +67,6 @@
 
 func init() {
 	__vdl.Register(SignedHeader{})
+	__vdl.Register(HashCode{})
 	__vdl.Register(SignedData(SignedDataSignature{security.Signature{}}))
 }