Default to BBR congestion control for QUIC. Protected by

net/quic/core/quic_session.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.
 //
 // A QuicSession, which demuxes a single connection to individual streams.
 
 #ifndef NET_QUIC_CORE_QUIC_SESSION_H_
 #define NET_QUIC_CORE_QUIC_SESSION_H_
 
 #include <cstddef>
@@ skipping 197 matching lines @@
   // Returns the number of "available" streams, the stream ids less than
   // largest_peer_created_stream_id_ that have not yet been opened.
   size_t GetNumAvailableStreams() const;
 
   // Add the stream to the session's write-blocked list because it is blocked by
   // connection-level flow control but not by its own stream-level flow control.
   // The stream will be given a chance to write when a connection-level
   // WINDOW_UPDATE arrives.
   void MarkConnectionLevelWriteBlocked(QuicStreamId id);
 
-  // Called by a stream when it becomes deletable.
-  void MarkStreamDeletable(QuicStreamId id);
+  // Called when stream |id| is done waiting for acks either because all data
+  // gets acked or is not interested in data being acked (which happens when
+  // a stream is reset because of an error).
+  void OnStreamDoneWaitingForAcks(QuicStreamId id);

[Ryan Hamilton, 2017/06/01 15:23:40]

This doesn't seem related to BBR. Did the BBR change get commingled with the
"waiting for acks" change?

 
   // Returns true if the session has data to be sent, either queued in the
   // connection, or in a write-blocked stream.
   bool HasDataToWrite() const;
 
   bool goaway_sent() const;
 
   bool goaway_received() const;
 
   QuicErrorCode error() const { return error_; }
@@ skipping 282 matching lines @@
 
   // This session is notified on every ack or loss.
   const bool use_stream_notifier_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CORE_QUIC_SESSION_H_