[sync] Componentize sync: Part 2: Add SYNC_EXPORTs to files in src/sync/

sync/util/get_session_name.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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 SYNC_UTIL_GET_SESSION_NAME_H_
 #define SYNC_UTIL_GET_SESSION_NAME_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
+#include "sync/base/sync_export.h"
 
 namespace base {
 class TaskRunner;
 }  // namespace base
 
 namespace syncer {
 
-void GetSessionName(
+SYNC_EXPORT void GetSessionName(
     const scoped_refptr<base::TaskRunner>& task_runner,
     const base::Callback<void(const std::string&)>& done_callback);
 
 std::string GetSessionNameSynchronouslyForTesting();
 
 }  // namespace syncer
 
 #endif  // SYNC_UTIL_GET_SESSION_NAME_H_