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

sync/engine/syncer_proto_util.cc

Index: sync/engine/syncer_proto_util.cc
diff --git a/sync/engine/syncer_proto_util.cc b/sync/engine/syncer_proto_util.cc
index e88bc066b16d2b5ffe9ada29e84c88bfa0c268c1..cac0516c03b27f0531a8f0c66fde721a3d90ab37 100644
--- a/sync/engine/syncer_proto_util.cc
+++ b/sync/engine/syncer_proto_util.cc
@@ -21,9 +21,12 @@
 #include "sync/syncable/syncable-inl.h"
 #include "sync/util/time.h"
 
-using syncer::SyncProtocolErrorType;
 using std::string;
 using std::stringstream;
+
+namespace syncer {
+
+using sessions::SyncSession;
 using syncable::BASE_VERSION;
 using syncable::CTIME;
 using syncable::ID;
@@ -33,9 +36,6 @@ using syncable::IS_UNSYNCED;
 using syncable::MTIME;
 using syncable::PARENT_ID;
 
-namespace syncer {
-using sessions::SyncSession;
-
 namespace {
 
 // Time to backoff syncing after receiving a throttled response.