[Sync] Implements the loopback sync server.

components/sync/engine_impl/syncer_proto_util.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SYNC_ENGINE_IMPL_SYNCER_PROTO_UTIL_H_
 #define COMPONENTS_SYNC_ENGINE_IMPL_SYNCER_PROTO_UTIL_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
@@ skipping 116 matching lines @@
   // Post the message using the scm, and do some processing on the returned
   // headers. Decode the server response.
   static bool PostAndProcessHeaders(ServerConnectionManager* scm,
                                     SyncCycle* cycle,
                                     const sync_pb::ClientToServerMessage& msg,
                                     sync_pb::ClientToServerResponse* response);
 
   static base::TimeDelta GetThrottleDelay(
       const sync_pb::ClientToServerResponse& response);
 
+  friend class LoopbackServerTest;
   friend class SyncerProtoUtilTest;
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, AddRequestBirthday);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, PostAndProcessHeaders);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, HandleThrottlingNoDatatypes);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, HandleThrottlingWithDatatypes);
 
   DISALLOW_COPY_AND_ASSIGN(SyncerProtoUtil);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_IMPL_SYNCER_PROTO_UTIL_H_