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

sync/engine/net/server_connection_manager.h

Index: sync/engine/net/server_connection_manager.h
diff --git a/sync/engine/net/server_connection_manager.h b/sync/engine/net/server_connection_manager.h
index a94582b01719c20820a2381734c2febe0bcf3c3e..3f7cce227547b5ed607ce776846d208f2e931a85 100644
--- a/sync/engine/net/server_connection_manager.h
+++ b/sync/engine/net/server_connection_manager.h
@@ -18,16 +18,16 @@
 #include "base/threading/thread_checker.h"
 #include "sync/syncable/syncable_id.h"
 
-namespace syncable {
-class Directory;
-}
-
 namespace sync_pb {
 class ClientToServerMessage;
 }
 
 namespace syncer {
 
+namespace syncable {
+class Directory;
+}
+
 static const int32 kUnsetResponseCode = -1;
 static const int32 kUnsetContentLength = -1;
 static const int32 kUnsetPayloadLength = -1;