Sort camera device list to use front camera first

media/capture/video/linux/video_capture_device_factory_linux.cc

Index: media/capture/video/linux/video_capture_device_factory_linux.cc
diff --git a/media/capture/video/linux/video_capture_device_factory_linux.cc b/media/capture/video/linux/video_capture_device_factory_linux.cc
index 14a1ca12e6b4c5679e1ed4efd5fc3df4b9aae3a2..5c4eeee616f53d593bcacfb9f27c54e66611c702 100644
--- a/media/capture/video/linux/video_capture_device_factory_linux.cc
+++ b/media/capture/video/linux/video_capture_device_factory_linux.cc
@@ -228,6 +228,10 @@ void VideoCaptureDeviceFactoryLinux::GetDeviceDescriptors(
 #endif
     }
   }
+  // Since JS doesn't have API to get camera facing, we sort the list to make
+  // sure apps 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());
 }
 
 void VideoCaptureDeviceFactoryLinux::GetSupportedFormats(