Pass camera facing to WebKit

content/renderer/media/media_stream_video_track.cc

Index: content/renderer/media/media_stream_video_track.cc
diff --git a/content/renderer/media/media_stream_video_track.cc b/content/renderer/media/media_stream_video_track.cc
index dede54fecb104f1e46e97f43eb0ba1d2ed1dea20..a8c1a2a94cd9a06d23c47a6d2fa7d60239896e31 100644
--- a/content/renderer/media/media_stream_video_track.cc
+++ b/content/renderer/media/media_stream_video_track.cc
@@ -307,6 +307,25 @@ void MediaStreamVideoTrack::getSettings(
       settings.frameRate = format->frame_rate;
       settings.width = format->frame_size.width();
       settings.height = format->frame_size.height();
+      const media::VideoFacingMode facing = source_->GetVideoFacing();
+      switch (facing) {
+        case media::VideoFacingMode::USER:
+          settings.facingMode =
+              blink::WebMediaStreamTrack::Settings::VideoFacingMode::User;
+          break;
+        case media::VideoFacingMode::ENVIRONMENT:
+          settings.facingMode = blink::WebMediaStreamTrack::Settings::
+              VideoFacingMode::Environment;
+          break;
+        case media::VideoFacingMode::LEFT:
+          settings.facingMode =
+              blink::WebMediaStreamTrack::Settings::VideoFacingMode::Left;
+          break;
+        case media::VideoFacingMode::RIGHT:
+          settings.facingMode =
+              blink::WebMediaStreamTrack::Settings::VideoFacingMode::Right;
+          break;
+      }

[mcasas, 2017/01/11 22:24:58]

And here, if we get a media::VideoFacingMode::None, don't
fill in |facing|. Which should do the trick assuming it has been 
changed to base::Optional<> as mentioned elsewhere.

[shenghao, 2017/01/12 08:10:48]

Done.

     }
   }
   // TODO(hta): Extract the real value.