Cleanup: IWYU for base/gtest_prod_util.h.

sync/internal_api/public/attachments/attachment_downloader_impl.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 SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_DOWNLOADER_IMPL_H_
 #define SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_DOWNLOADER_IMPL_H_
 
 #include "base/containers/scoped_ptr_hash_map.h"
+#include "base/gtest_prod_util.h"
 #include "base/threading/non_thread_safe.h"
 #include "google_apis/gaia/oauth2_token_service_request.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "sync/internal_api/public/attachments/attachment_downloader.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "url/gurl.h"
 
 namespace base {
 class RefCountedMemory;
@@ skipping 98 matching lines @@
   StateList requests_waiting_for_access_token_;
 
   ModelType model_type_;
 
   DISALLOW_COPY_AND_ASSIGN(AttachmentDownloaderImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_DOWNLOADER_IMPL_H_