Pass camera facing to WebKit

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>
 
 #include "content/common/content_export.h"
 
 namespace media {
 struct AudioDeviceDescription;
+struct VideoCaptureDeviceDescriptor;
 }
 
 namespace content {
 
 enum MediaDeviceType {
   MEDIA_DEVICE_TYPE_AUDIO_INPUT,
   MEDIA_DEVICE_TYPE_VIDEO_INPUT,
   MEDIA_DEVICE_TYPE_AUDIO_OUTPUT,
   NUM_MEDIA_DEVICE_TYPES,
 };
 
 struct CONTENT_EXPORT MediaDeviceInfo {
   MediaDeviceInfo() = default;
   MediaDeviceInfo(const std::string& device_id,
                   const std::string& label,
                   const std::string& group_id);
   explicit MediaDeviceInfo(
       const media::AudioDeviceDescription& device_description);
 
+  explicit MediaDeviceInfo(
+      const media::VideoCaptureDeviceDescriptor& descriptor);
   std::string device_id;
   std::string label;
   std::string group_id;
+  // Format is "vid:pid". Ex. "E2A1:34D0".
+  std::string model_id;

[jochen (gone - plz use gerrit), 2017/01/05 12:17:59]

why not a pair of ints then?

[shenghao, 2017/01/06 09:43:01]

We use the formatted "vid:pid" string as identifier in camera config files. When
we get model_id from VideoCaptureDeviceDescriptor, it's already in this format,
so converting it to 2 ints and back seems redundant. Plus that separated vid or
pid are not useful anywhere in the system.  

[wuchengli, 2017/01/09 08:28:00]

Another reason is we'll have non-USB cameras soon. Those cameras do not have vid
and pid.

 };
 
 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_