This CL adds methods to manipulate RTP header extension, particularly

content/browser/renderer_host/p2p/socket_host.h

Index: content/browser/renderer_host/p2p/socket_host.h
diff --git a/content/browser/renderer_host/p2p/socket_host.h b/content/browser/renderer_host/p2p/socket_host.h
index 46fcde5b7d56a22a815f1a0cf850b2fa538c4252..cc1463b3b1b98bc25b06714ed9eea3fb21d0bd73 100644
--- a/content/browser/renderer_host/p2p/socket_host.h
+++ b/content/browser/renderer_host/p2p/socket_host.h
@@ -53,7 +53,9 @@ class CONTENT_EXPORT P2PSocketHost {
   virtual bool SetOption(P2PSocketOption option, int value) = 0;
 
  protected:
-  friend class P2PSocketHostTcpTestBase;
+
+  void MaybeUpdatePacketSendTimeExtn(char* data, int length,
+                                     const talk_base::PacketOptions& options);
 
   // TODO(mallinath) - Remove this below enum and use one defined in
   // libjingle/souce/talk/p2p/base/stun.h
@@ -97,6 +99,16 @@ class CONTENT_EXPORT P2PSocketHost {
                                 StunMessageType* type);
   static bool IsRequestOrResponse(StunMessageType type);
 
+  bool MaybeUpdateRtpSendTimeExtn(char* rtp, int length,
+                                  int extension_id);
+  bool GetRtpPacketStartPositionAndLength(char* data, int length,
+                                          int* rtp_start_pos,
+                                          int* rtp_packet_length);
+  void UpdateSendTimeExtnValue(char* data, int len);
+
+  void MaybeUpdateRtpAuthTag(char* packet, int len,
+                             const talk_base::PacketOptions& options);
+
   IPC::Sender* message_sender_;
   int id_;
   State state_;