Make OverheadObserver::OnOverheadChanged count RTP headers only

webrtc/modules/rtp_rtcp/include/rtp_rtcp.h

Index: webrtc/modules/rtp_rtcp/include/rtp_rtcp.h
diff --git a/webrtc/modules/rtp_rtcp/include/rtp_rtcp.h b/webrtc/modules/rtp_rtcp/include/rtp_rtcp.h
index 27e6143ae27c86e6c35a7a8738e322c763867fe8..8d1ee6d1057cb5b7b47a0838d0ae24be077c7496 100644
--- a/webrtc/modules/rtp_rtcp/include/rtp_rtcp.h
+++ b/webrtc/modules/rtp_rtcp/include/rtp_rtcp.h
@@ -115,36 +115,20 @@ class RtpRtcp : public Module {
   // Sender
   // **************************************************************************
 
-  // Sets MTU.
-  // |size| - Max transfer unit in bytes, default is 1500.
-  // Returns -1 on failure else 0.
-  virtual int32_t SetMaxTransferUnit(uint16_t size) = 0;
-
-  // Sets transport overhead. Default is IPv4 and UDP with no encryption.
-  // |tcp| - true for TCP false UDP.
-  // |ipv6| - true for IP version 6 false for version 4.
-  // |authentication_overhead| - number of bytes to leave for an authentication
-  // header.
-  // Returns -1 on failure else 0
-  // TODO(michaelt): deprecate the function.
-  virtual int32_t SetTransportOverhead(bool tcp,
-                                       bool ipv6,
-                                       uint8_t authentication_overhead = 0) = 0;
-
-  // Sets transport overhead per packet.
-  virtual void SetTransportOverhead(int transport_overhead_per_packet) = 0;
-
-  // Returns max payload length, which is a combination of the configuration
-  // MaxTransferUnit and TransportOverhead.
+  // TODO(nisse): Use int or size_t?
+  // Sets the maximum size of an RTP packet, including RTP headers.
+  virtual void SetMaxRtpPacketSize(size_t size) = 0;
+
+  // Returns max payload length.
   // Does not account for RTP headers and FEC/ULP/RED overhead (when FEC is
   // enabled).
-  virtual uint16_t MaxPayloadLength() const = 0;
+  virtual size_t MaxPayloadSize() const = 0;
 
   // Returns max data payload length, which is a combination of the
   // configuration MaxTransferUnit, headers and TransportOverhead.
   // Takes into account RTP headers and FEC/ULP/RED overhead (when FEC is
   // enabled).
-  virtual uint16_t MaxDataPayloadLength() const = 0;
+  virtual size_t MaxRtpPacketSize() const = 0;
 
   // Sets codec name and payload type. Returns -1 on failure else 0.
   virtual int32_t RegisterSendPayload(const CodecInst& voice_codec) = 0;