Make Quic client more memory efficient. Protected by --quic_headers_stream_release_sequencer_buffer.

net/quic/core/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 <stddef.h>
 
 #include <memory>
@@ skipping 98 matching lines @@
                                  bool fin);
 
   bool force_hol_blocking() const { return force_hol_blocking_; }
 
   bool server_push_enabled() const { return server_push_enabled_; }
 
   // Called by |QuicHeadersStream::UpdateEnableServerPush()| with
   // value from SETTINGS_ENABLE_PUSH.
   void set_server_push_enabled(bool enable) { server_push_enabled_ = enable; }
 
+  // Return true if this session wants to release headers stream's buffer
+  // aggressively.
+  virtual bool ShouldReleaseHeadersStreamSequencerBuffer();
+
  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(SpdyPriority priority) override =
       0;
 
   QuicSpdyStream* GetSpdyDataStream(const QuicStreamId stream_id);
 
@@ skipping 16 matching lines @@
   // Set during handshake. If true, resources in x-associated-content and link
   // headers will be pushed.
   bool server_push_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSpdySession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SPDY_SESSION_H_