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

chrome/browser/sync_file_system/file_change.h

 // Copyright 2013 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 CHROME_BROWSER_SYNC_FILE_SYSTEM_FILE_CHANGE_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_FILE_CHANGE_H_
 
 #include <stddef.h>
 
 #include <deque>
@@ skipping 34 matching lines @@
  private:
   ChangeType change_;
   SyncFileType file_type_;
 };
 
 class FileChangeList {
  public:
   typedef std::deque<FileChange> List;
 
   FileChangeList();
+  FileChangeList(const FileChangeList& other);
   ~FileChangeList();
 
   // Updates the list with the |new_change|.
   void Update(const FileChange& new_change);
 
   size_t size() const { return list_.size(); }
   bool empty() const { return list_.empty(); }
   void clear() { list_.clear(); }
   const List& list() const { return list_; }
   const FileChange& front() const { return list_.front(); }
   const FileChange& back() const { return list_.back(); }
 
   FileChangeList PopAndGetNewList() const;
 
   std::string DebugString() const;
 
  private:
   List list_;
 };
 
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_FILE_CHANGE_H_