SignalPacketReceived should pass packet as a pointer instead of a non-const reference.

webrtc/pc/channel.h

Index: webrtc/pc/channel.h
diff --git a/webrtc/pc/channel.h b/webrtc/pc/channel.h
index ae3a29a2ffb1de42f48340f57a264cb3292e0906..11d21212f8ee4ecb2d847431cea3433d5e32c638 100644
--- a/webrtc/pc/channel.h
+++ b/webrtc/pc/channel.h
@@ -271,7 +271,7 @@ class BaseChannel
                     const rtc::PacketTime& packet_time);
   // TODO(zstein): packet can be const once the RtpTransport handles protection.
   virtual void OnPacketReceived(bool rtcp,
-                                rtc::CopyOnWriteBuffer& packet,
+                                rtc::CopyOnWriteBuffer* packet,
                                 const rtc::PacketTime& packet_time);
   void ProcessPacket(bool rtcp,
                      const rtc::CopyOnWriteBuffer& packet,
@@ -505,7 +505,7 @@ class VoiceChannel : public BaseChannel {
  private:
   // overrides from BaseChannel
   void OnPacketReceived(bool rtcp,
-                        rtc::CopyOnWriteBuffer& packet,
+                        rtc::CopyOnWriteBuffer* packet,
                         const rtc::PacketTime& packet_time) override;
   void UpdateMediaSendRecvState_w() override;
   const ContentInfo* GetFirstContent(const SessionDescription* sdesc) override;