Detect situation when there is no missing send completion signal in P2PSocket implementation.

content/renderer/p2p/socket_client.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_P2P_SOCKET_CLIENT_H_
 #define CONTENT_RENDERER_P2P_SOCKET_CLIENT_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
@@ skipping 23 matching lines @@
       const net::IPEndPoint& remote_address,
       P2PSocketClientDelegate* delegate);
 
   P2PSocketClient() {}
 
   // Send the |data| to the |address|.
   virtual void Send(const net::IPEndPoint& address,
                     const std::vector<char>& data) = 0;
 
   // Send the |data| to the |address| using Differentiated Services Code Point
-  // |dscp|.
-  virtual void SendWithDscp(const net::IPEndPoint& address,
-                            const std::vector<char>& data,
-                            const rtc::PacketOptions& options) = 0;
+  // |dscp|. Return value is the unique packet_id for this packet.
+  virtual uint64 SendWithDscp(const net::IPEndPoint& address,
+                              const std::vector<char>& data,
+                              const rtc::PacketOptions& options) = 0;
 
   virtual void SetOption(P2PSocketOption option, int value) = 0;
 
   // Must be called before the socket is destroyed.
   virtual void Close() = 0;
 
   virtual int GetSocketID() const = 0;
   virtual void SetDelegate(P2PSocketClientDelegate* delegate) = 0;
 
  protected:
   virtual ~P2PSocketClient() {}
 
  private:
   // Calls destructor.
   friend class base::RefCountedThreadSafe<P2PSocketClient>;
 };
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_P2P_SOCKET_CLIENT_H_