[Mojo Video Capture] Introduce abstraction VideoCaptureSystem

media/capture/video/video_capture_device_info.cc

+// Copyright 2017 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 "media/capture/video/video_capture_device_info.h"
+
+namespace media {
+
+VideoCaptureDeviceInfo::VideoCaptureDeviceInfo() = default;
+
+VideoCaptureDeviceInfo::VideoCaptureDeviceInfo(
+    media::VideoCaptureDeviceDescriptor descriptor)
+    : descriptor(descriptor) {}
+
+VideoCaptureDeviceInfo::VideoCaptureDeviceInfo(
+    const VideoCaptureDeviceInfo& other) = default;
+
+VideoCaptureDeviceInfo::~VideoCaptureDeviceInfo() = default;
+
+VideoCaptureDeviceInfo& VideoCaptureDeviceInfo::operator=(
+    const VideoCaptureDeviceInfo& other) = default;
+
+}  // namespace media