Add constructors and operators to MediaDeviceInfo.

content/common/media/media_devices.cc

 // Copyright 2016 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.
 
 #include "content/common/media/media_devices.h"
 #include "media/audio/audio_device_description.h"
+#include "media/capture/video/video_capture_device_descriptor.h"
 
 namespace content {
 
+MediaDeviceInfo::MediaDeviceInfo() = default;
+
+MediaDeviceInfo::MediaDeviceInfo(const MediaDeviceInfo& other) = default;
+
+MediaDeviceInfo::MediaDeviceInfo(MediaDeviceInfo&& other) = default;
+
 MediaDeviceInfo::MediaDeviceInfo(const std::string& device_id,
                                  const std::string& label,
                                  const std::string& group_id)
     : device_id(device_id), label(label), group_id(group_id) {}
 
 MediaDeviceInfo::MediaDeviceInfo(
     const media::AudioDeviceDescription& device_description)
     : device_id(device_description.unique_id),
       label(device_description.device_name),
       group_id(device_description.group_id) {}
 
+MediaDeviceInfo::MediaDeviceInfo(
+    const media::VideoCaptureDeviceDescriptor& descriptor)
+    : device_id(descriptor.device_id), label(descriptor.GetNameAndModel()) {}
+
+MediaDeviceInfo::~MediaDeviceInfo() = default;
+
+MediaDeviceInfo& MediaDeviceInfo::operator=(const MediaDeviceInfo& other) =
+    default;
+
+MediaDeviceInfo& MediaDeviceInfo::operator=(MediaDeviceInfo&& other) = default;
+
 bool operator==(const MediaDeviceInfo& first, const MediaDeviceInfo& second) {
   return first.device_id == second.device_id && first.label == second.label;
 }
 
 }  // namespace content