--- a/media/webrtc/signaling/src/media-conduit/VideoConduit.h
+++ b/media/webrtc/signaling/src/media-conduit/VideoConduit.h
@@ -442,17 +442,17 @@ private:
   bool CodecsDifferent(const nsTArray<UniquePtr<VideoCodecConfig>>& a,
                        const nsTArray<UniquePtr<VideoCodecConfig>>& b);
 
   // Factory class for VideoStreams... vie_encoder.cc will call this to reconfigure.
   // We need to give it access to the conduit to make it's decisions
   class VideoStreamFactory : public webrtc::VideoEncoderConfig::VideoStreamFactoryInterface
   {
   public:
-    VideoStreamFactory(std::string aCodecName,
+    VideoStreamFactory(const std::string& aCodecName,
                        WebrtcVideoConduit *aConduit)
       : mCodecName(aCodecName),
         mConduit(aConduit) {}
 
   private:
     std::vector<webrtc::VideoStream>
       CreateEncoderStreams(int width, int height,
                            const webrtc::VideoEncoderConfig& config) override;