Add QuicConnectionCloseDelegateInterface. No functional change expected. Not protected.

net/quic/quic_protocol.h

 // Copyright (c) 2012 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 NET_QUIC_QUIC_PROTOCOL_H_
 #define NET_QUIC_QUIC_PROTOCOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1334 matching lines @@
   // |retransmitted_bytes| is the number of data bytes retransmitted.
   virtual void OnPacketRetransmitted(int retransmitted_bytes) = 0;
 
  protected:
   friend class base::RefCounted<QuicAckListenerInterface>;
 
   // Delegates are ref counted.
   virtual ~QuicAckListenerInterface() {}
 };
 
+// Pure virtual class to close connection on unrecoverable errors.
+class NET_EXPORT_PRIVATE QuicConnectionCloseDelegateInterface {
+ public:
+  virtual ~QuicConnectionCloseDelegateInterface() {}
+
+  // Called when an unrecoverable error is encountered.
+  virtual void OnUnrecoverableError(QuicErrorCode error,
+                                    const std::string& error_details,
+                                    ConnectionCloseSource source) = 0;
+};
+
 struct NET_EXPORT_PRIVATE AckListenerWrapper {
   AckListenerWrapper(QuicAckListenerInterface* listener,
                      QuicPacketLength data_length);
   AckListenerWrapper(const AckListenerWrapper& other);
   ~AckListenerWrapper();
 
   scoped_refptr<QuicAckListenerInterface> ack_listener;
   QuicPacketLength length;
 };
 
@@ skipping 111 matching lines @@
       : iov(iov), iov_count(iov_count), total_length(total_length) {}
 
   const struct iovec* iov;
   const int iov_count;
   const size_t total_length;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PROTOCOL_H_