Sort camera device list to use front camera first

media/capture/video/linux/video_capture_device_factory_linux.cc

 // Copyright 2014 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/linux/video_capture_device_factory_linux.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stdint.h>
 #include <sys/ioctl.h>
@@ skipping 210 matching lines @@
           VideoCaptureApi::LINUX_V4L2_SINGLE_PLANE,
           VideoCaptureTransportType::OTHER_TRANSPORT,
           g_camera_facing_helper.Get().GetCameraFacing(unique_id, model_id));
 #else
       device_descriptors->emplace_back(
           reinterpret_cast<char*>(cap.card), unique_id, model_id,
           VideoCaptureApi::LINUX_V4L2_SINGLE_PLANE);
 #endif
     }
   }
+  // Since JS doesn't have API to get camera facing, we sort the list to make
+  // apps can use the front camera by default.
+  // TODO(henryhsu): remove this after JS API completed (crbug.com/543997).
+  std::sort(device_descriptors->begin(), device_descriptors->end());

[Guido Urdaneta, 2017/01/24 10:42:07]

Is this sorting relevant only for linux, or should it apply to other platforms
as well?

[henryhsu, 2017/01/25 03:28:18]

This is for chromebook

 }
 
 void VideoCaptureDeviceFactoryLinux::GetSupportedFormats(
     const VideoCaptureDeviceDescriptor& device,
     VideoCaptureFormats* supported_formats) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (device.device_id.empty())
     return;
   base::ScopedFD fd(HANDLE_EINTR(open(device.device_id.c_str(), O_RDONLY)));
   if (!fd.is_valid())  // Failed to open this device.
@@ skipping 28 matching lines @@
 }
 
 // static
 VideoCaptureDeviceFactory*
 VideoCaptureDeviceFactory::CreateVideoCaptureDeviceFactory(
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
   return new VideoCaptureDeviceFactoryLinux(ui_task_runner);
 }
 
 }  // namespace media