[Sync] Convert sync to a static library.

components/sync/base/time.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.
 //
 // Time-related sync functions.
 
 #ifndef COMPONENTS_SYNC_BASE_TIME_H_
 #define COMPONENTS_SYNC_BASE_TIME_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/time/time.h"
-#include "components/sync/base/sync_export.h"
 
 namespace syncer {
 
 // Converts a time object to the format used in sync protobufs (ms
 // since the Unix epoch).
-SYNC_EXPORT int64_t TimeToProtoTime(const base::Time& t);
+int64_t TimeToProtoTime(const base::Time& t);
 
 // Converts a time field from sync protobufs to a time object.
-SYNC_EXPORT base::Time ProtoTimeToTime(int64_t proto_t);
+base::Time ProtoTimeToTime(int64_t proto_t);
 
-SYNC_EXPORT std::string GetTimeDebugString(const base::Time& t);
+std::string GetTimeDebugString(const base::Time& t);
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_BASE_TIME_H_