components: Add out-of-line copy ctors for complex classes.

components/history/core/browser/download_row.h

 // Copyright (c) 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_HISTORY_CORE_BROWSER_DOWNLOAD_ROW_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_DOWNLOAD_ROW_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 23 matching lines @@
               const std::string& last_modified,
               int64_t received,
               int64_t total,
               DownloadState download_state,
               DownloadDangerType danger_type,
               DownloadInterruptReason interrupt_reason,
               DownloadId id,
               bool download_opened,
               const std::string& ext_id,
               const std::string& ext_name);
+  DownloadRow(const DownloadRow& other);
   ~DownloadRow();
 
   // The current path to the download (potentially different from final if
   // download is in progress or interrupted).
   base::FilePath current_path;
 
   // The target path where the download will go when it's complete.
   base::FilePath target_path;
 
   // The URL redirect chain through which we are downloading.  The front
@@ skipping 46 matching lines @@
   bool opened;
 
   // The id and name of the extension that created this download.
   std::string by_ext_id;
   std::string by_ext_name;
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_DOWNLOAD_ROW_H_