Remove device enumeration, caching and monitoring from MediaStreamManager.

content/common/media/media_devices.h

+// 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.
+
+#ifndef CONTENT_COMMON_MEDIA_MEDIA_DEVICES_H_
+#define CONTENT_COMMON_MEDIA_MEDIA_DEVICES_H_
+
+#include <string>
+#include <vector>
+
+namespace content {
+
+enum MediaDeviceType {
+  MEDIA_DEVICE_TYPE_AUDIO_INPUT,
+  MEDIA_DEVICE_TYPE_VIDEO_INPUT,
+  MEDIA_DEVICE_TYPE_AUDIO_OUTPUT,
+  NUM_MEDIA_DEVICE_TYPES,
+};
+
+struct MediaDeviceInfo {
+  MediaDeviceInfo(const std::string& device_id,
+                  const std::string& label,
+                  const std::string& group_id);
+  std::string device_id;
+  std::string label;
+  std::string group_id;
+};
+
+using MediaDeviceInfoArray = std::vector<MediaDeviceInfo>;
+
+bool operator==(const MediaDeviceInfo& first, const MediaDeviceInfo& second);
+
+inline bool IsValidMediaDeviceType(MediaDeviceType type) {
+  return type >= 0 && type < NUM_MEDIA_DEVICE_TYPES;
+}
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_MEDIA_MEDIA_DEVICES_H_