[Sync] Move sync/{internal_api,syncable} into syncer namespace

sync/internal_api/public/syncable/model_type_payload_map.h

Index: sync/internal_api/public/syncable/model_type_payload_map.h
diff --git a/sync/internal_api/public/syncable/model_type_payload_map.h b/sync/internal_api/public/syncable/model_type_payload_map.h
index 5ea9919195d170d036d3c50a123ed65a1be49a03..077206bf62f9eba1003d9975bafdbd0c86057c23 100644
--- a/sync/internal_api/public/syncable/model_type_payload_map.h
+++ b/sync/internal_api/public/syncable/model_type_payload_map.h
@@ -18,6 +18,7 @@ namespace base {
 class DictionaryValue;
 }
 
+namespace syncer {
 namespace syncable {
 
 // A container that contains a set of datatypes with possible string
@@ -56,5 +57,21 @@ void PurgeStalePayload(ModelTypePayloadMap* original,
                        const syncer::ModelSafeRoutingInfo& routing_info);
 
 }  // namespace syncable
+}  // namespace syncer
+
+// TODO(akalin): Move the names below to the 'syncer' namespace once
+// we move this file to public/base.
+namespace syncable {
+
+using ::syncer::syncable::ModelTypePayloadMap;
+using ::syncer::syncable::ModelTypePayloadMapFromEnumSet;
+using ::syncer::syncable::ModelTypePayloadMapToEnumSet;
+using ::syncer::syncable::ModelTypePayloadMapFromRoutingInfo;
+using ::syncer::syncable::ModelTypePayloadMapToString;
+using ::syncer::syncable::ModelTypePayloadMapToValue;
+using ::syncer::syncable::CoalescePayloads;
+using ::syncer::syncable::PurgeStalePayload;
+
+}  // namespace syncable
 
 #endif  // SYNC_INTERNAL_PUBLIC_API_SYNCABLE_MODEL_TYPE_PAYLOAD_MAP_H_