[Cronet] Make delaying sending request headers explicit in bidirectional stream

net/quic/bidirectional_stream_quic_impl.h

 // Copyright 2016 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_BIDIRECTIONAL_STREAM_QUIC_IMPL_H_
 #define NET_QUIC_BIDIRECTIONAL_STREAM_QUIC_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 21 matching lines @@
       public QuicChromiumClientSession::Observer {
  public:
   explicit BidirectionalStreamQuicImpl(
       const base::WeakPtr<QuicChromiumClientSession>& session);
 
   ~BidirectionalStreamQuicImpl() override;
 
   // BidirectionalStreamImpl implementation:
   void Start(const BidirectionalStreamRequestInfo* request_info,
              const BoundNetLog& net_log,
-             bool disable_auto_flush,
+             bool delay_headers_until_next_send_data,
              BidirectionalStreamImpl::Delegate* delegate,
              std::unique_ptr<base::Timer> timer) override;
   int ReadData(IOBuffer* buffer, int buffer_len) override;
   void SendData(const scoped_refptr<IOBuffer>& data,
                 int length,
                 bool end_stream) override;
   void SendvData(const std::vector<scoped_refptr<IOBuffer>>& buffers,
                  const std::vector<int>& lengths,
                  bool end_stream) override;
   void Cancel() override;
@@ skipping 51 matching lines @@
   // bytes received over the network for |stream_| while it was open.
   int64_t closed_stream_received_bytes_;
   // After |stream_| has been closed, this keeps track of the total number of
   // bytes sent over the network for |stream_| while it was open.
   int64_t closed_stream_sent_bytes_;
   // Indicates whether initial headers have been sent.
   bool has_sent_headers_;
   // Indicates whether initial headers have been received.
   bool has_received_headers_;
 
-  bool disable_auto_flush_;
+  // Whether to delay sending request headers until next SendData/SendvData,
+  // so header frame can be coalesced with data frame in the same packet.
+  bool delay_headers_until_next_send_data_;
 
   base::WeakPtrFactory<BidirectionalStreamQuicImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BidirectionalStreamQuicImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_BIDIRECTIONAL_STREAM_QUIC_IMPL_H_