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

media/base/cdm_key_information.h

 // Copyright 2015 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 MEDIA_BASE_CDM_KEY_INFORMATION_H_
 #define MEDIA_BASE_CDM_KEY_INFORMATION_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 22 matching lines @@
   CdmKeyInformation(const std::vector<uint8_t>& key_id,
                     KeyStatus status,
                     uint32_t system_code);
   CdmKeyInformation(const std::string& key_id,
                     KeyStatus status,
                     uint32_t system_code);
   CdmKeyInformation(const uint8_t* key_id_data,
                     size_t key_id_length,
                     KeyStatus status,
                     uint32_t system_code);
+  CdmKeyInformation(const CdmKeyInformation& other);
   ~CdmKeyInformation();
 
   std::vector<uint8_t> key_id;
   KeyStatus status;
   uint32_t system_code;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_CDM_KEY_INFORMATION_H_