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

chromeos/audio/audio_device.h

 // Copyright (c) 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 CHROMEOS_AUDIO_AUDIO_DEVICE_H_
 #define CHROMEOS_AUDIO_AUDIO_DEVICE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 17 matching lines @@
   AUDIO_TYPE_KEYBOARD_MIC,
   AUDIO_TYPE_AOKR,
   AUDIO_TYPE_POST_MIX_LOOPBACK,
   AUDIO_TYPE_POST_DSP_LOOPBACK,
   AUDIO_TYPE_OTHER,
 };
 
 struct CHROMEOS_EXPORT AudioDevice {
   AudioDevice();
   explicit AudioDevice(const AudioNode& node);
+  AudioDevice(const AudioDevice& other);
   std::string ToString() const;
 
   // Converts between the string type sent via D-Bus and AudioDeviceType.
   // Static so they can be used by tests.
   static std::string GetTypeString(chromeos::AudioDeviceType type);
   static chromeos::AudioDeviceType GetAudioType(const std::string& node_type);
 
   // Indicates that an input or output audio device is for simple usage like
   // playback or recording for user. In contrast, audio device such as
   // loopback, always on keyword recognition (AOKR), and keyboard mic are
@@ skipping 50 matching lines @@
       return true;
     } else {
       return false;
     }
   }
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_AUDIO_DEVICE_H_