[sync] Add WalletMetadataSpecifics protobuf.

sync/protocol/proto_enum_conversions.cc

Index: sync/protocol/proto_enum_conversions.cc
diff --git a/sync/protocol/proto_enum_conversions.cc b/sync/protocol/proto_enum_conversions.cc
index 9b7e7a4d7c9769ad6f33b6e8cf5ea6b0b8d14e9d..bafe31eb3d126e6e4f9fc29bd2f82b8e43c3a35e 100644
--- a/sync/protocol/proto_enum_conversions.cc
+++ b/sync/protocol/proto_enum_conversions.cc
@@ -214,6 +214,18 @@ const char* GetWalletInfoTypeString(
   return "";
 }
 
+const char* GetWalletMetadataTypeString(
+    sync_pb::WalletMetadataSpecifics::Type wallet_metadata_type) {
+  ASSERT_ENUM_BOUNDS(sync_pb::WalletMetadataSpecifics, Type, UNKNOWN, ADDRESS);
+  switch (wallet_metadata_type) {
+    ENUM_CASE(sync_pb::WalletMetadataSpecifics, UNKNOWN);
+    ENUM_CASE(sync_pb::WalletMetadataSpecifics, CARD);
+    ENUM_CASE(sync_pb::WalletMetadataSpecifics, ADDRESS);
+  }
+  NOTREACHED();
+  return "";
+}
+
 const char* GetWalletCardStatusString(
     sync_pb::WalletMaskedCreditCard::WalletCardStatus wallet_card_status) {
   switch (wallet_card_status) {