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

components/device_event_log/device_event_log_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 COMPONENTS_DEVICE_EVENT_LOG_DEVICE_EVENT_LOG_IMPL_H_
 #define COMPONENTS_DEVICE_EVENT_LOG_DEVICE_EVENT_LOG_IMPL_H_
 
 #include <stddef.h>
 
 #include <list>
@@ skipping 10 matching lines @@
 
 // Implementation class for DEVICE_LOG.
 class DEVICE_EVENT_LOG_EXPORT DeviceEventLogImpl {
  public:
   struct LogEntry {
     LogEntry(const char* filedesc,
              int file_line,
              LogType log_type,
              LogLevel log_level,
              const std::string& event);
+    LogEntry(const LogEntry& other);
 
     std::string file;
     int file_line;
     LogType log_type;
     LogLevel log_level;
     std::string event;
     base::Time time;
     int count;
   };
 
@@ skipping 40 matching lines @@
   size_t max_entries_;
   LogEntryList entries_;
   base::WeakPtrFactory<DeviceEventLogImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceEventLogImpl);
 };
 
 }  // namespace device_event_log
 
 #endif  // COMPONENTS_DEVICE_EVENT_LOG_DEVICE_EVENT_LOG_IMPL_H_