iOS: Fix rotation bug for back camera

webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm

Index: webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
diff --git a/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm b/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
index 4195f9bd37e804a79b79f73d914b010f3b798421..f104b9dc46cb9d4c3bfbcad2ba96d6b91d87fb21 100644
--- a/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
+++ b/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
@@ -629,10 +629,12 @@ static BOOL SetFormatForCaptureDevice(AVCaptureDevice *device,
       _rotation = webrtc::kVideoRotation_270;
       break;
     case UIDeviceOrientationLandscapeLeft:
-      _rotation = webrtc::kVideoRotation_180;
+      _rotation = _capturer->GetUseBackCamera() ? webrtc::kVideoRotation_0
+                                                : webrtc::kVideoRotation_180;
       break;
     case UIDeviceOrientationLandscapeRight:
-      _rotation = webrtc::kVideoRotation_0;
+      _rotation = _capturer->GetUseBackCamera() ? webrtc::kVideoRotation_180
+                                                : webrtc::kVideoRotation_0;
       break;
     case UIDeviceOrientationFaceUp:
     case UIDeviceOrientationFaceDown: