Reland of Add groupid for media devices. Group audio devices.

content/browser/renderer_host/media/audio_output_device_enumerator.h

Index: content/browser/renderer_host/media/audio_output_device_enumerator.h
diff --git a/content/browser/renderer_host/media/audio_output_device_enumerator.h b/content/browser/renderer_host/media/audio_output_device_enumerator.h
index 259adb543bd8bbc11755185a17fa0ae5d05ae8aa..c2504258fda14e6e0d17ebdb293d550b822e56e9 100644
--- a/content/browser/renderer_host/media/audio_output_device_enumerator.h
+++ b/content/browser/renderer_host/media/audio_output_device_enumerator.h
@@ -39,8 +39,19 @@ namespace content {
 // The enumerations returned by AudioOutputDeviceEnumerator::Enumerate() contain
 // elements of this type. It is used only in the browser side.
 struct AudioOutputDeviceInfo {
+  AudioOutputDeviceInfo();
+  AudioOutputDeviceInfo(const AudioOutputDeviceInfo& audio_output_device_info);
+  AudioOutputDeviceInfo(AudioOutputDeviceInfo&& audio_output_device_info);
+  AudioOutputDeviceInfo& operator=(
+      const AudioOutputDeviceInfo& audio_output_device_info);
+  AudioOutputDeviceInfo(const std::string& unique_id,
+                        const std::string& device_name,
+                        const std::string& group_id,
+                        media::AudioParameters output_params);
+  ~AudioOutputDeviceInfo();
   std::string unique_id;
   std::string device_name;
+  std::string group_id;
   media::AudioParameters output_params;
 };