Add a new method to QuicSpdySession

net/quic/quic_spdy_session.h

 // Copyright (c) 2015 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_SPDY_SESSION_H_
 #define NET_QUIC_QUIC_SPDY_SESSION_H_
 
 #include "net/quic/quic_headers_stream.h"
 #include "net/quic/quic_session.h"
 #include "net/quic/quic_spdy_stream.h"
@@ skipping 33 matching lines @@
   // If provided, |ack_notifier_delegate| will be registered to be notified when
   // we have seen ACKs for all packets resulting from this call.
   size_t WriteHeaders(QuicStreamId id,
                       const SpdyHeaderBlock& headers,
                       bool fin,
                       QuicPriority priority,
                       QuicAckListenerInterface* ack_notifier_delegate);
 
   QuicHeadersStream* headers_stream() { return headers_stream_.get(); }
 
+  // Called when Head of Line Blocking happens in the headers stream.
+  // |delta| indicates how long that piece of data has been blocked.
+  virtual void OnHeadersHeadOfLineBlocking(QuicTime::Delta delta);
+
  protected:
   // Override CreateIncomingDynamicStream() and CreateOutgoingDynamicStream()
   // with QuicSpdyStream return type to make sure that all data streams are
   // QuicSpdyStreams.
   QuicSpdyStream* CreateIncomingDynamicStream(QuicStreamId id) override = 0;
   QuicSpdyStream* CreateOutgoingDynamicStream() override = 0;
 
   QuicSpdyStream* GetSpdyDataStream(const QuicStreamId stream_id);
 
  private:
   friend class test::QuicSpdySessionPeer;
 
   scoped_ptr<QuicHeadersStream> headers_stream_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSpdySession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SPDY_SESSION_H_