[Sync] Convert sync to a static library.

components/sync/core/attachments/attachment_util.h

 // Copyright 2014 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_CORE_ATTACHMENTS_ATTACHMENT_UTIL_H_
 #define COMPONENTS_SYNC_CORE_ATTACHMENTS_ATTACHMENT_UTIL_H_
 
 #include <stdint.h>
 
 #include "base/memory/ref_counted.h"
-#include "components/sync/base/sync_export.h"
 
 namespace base {
 class RefCountedMemory;
 }
 
 namespace syncer {
 
 // Return the crc32c of the memory described by |data|.
 //
 // Potentially expensive.
 // Ideally this function should be static function in Attachment class, but
 // include_rules from sync/api/DEPS don't allow direct dependency on
 // third_party.
-SYNC_EXPORT uint32_t
-ComputeCrc32c(const scoped_refptr<base::RefCountedMemory>& data);
+uint32_t ComputeCrc32c(const scoped_refptr<base::RefCountedMemory>& data);
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_CORE_ATTACHMENTS_ATTACHMENT_UTIL_H_