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

net/spdy/bidirectional_stream_spdy_impl.h

 // Copyright 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_SPDY_BIDIRECTIONAL_STREAM_SPDY_IMPL_H_
 #define NET_SPDY_BIDIRECTIONAL_STREAM_SPDY_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 24 matching lines @@
       public SpdyStream::Delegate {
  public:
   explicit BidirectionalStreamSpdyImpl(
       const base::WeakPtr<SpdySession>& spdy_session);
 
   ~BidirectionalStreamSpdyImpl() 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* buf, int buf_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 37 matching lines @@
   // Whether OnClose has been invoked.
   bool stream_closed_;
   // Status reported in OnClose.
   int closed_stream_status_;
   // After |stream_| has been closed, this keeps track of the total number of
   // 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_;
-  // Whether auto flush is disabled.
-  bool disable_auto_flush_;
-  // Only relevant when |disable_auto_flush_| is true;
   // This is the combined buffer of buffers passed in through SendvData.
+  // Keep a reference here so it is alive until OnDataSent is invoked.
   scoped_refptr<IOBuffer> pending_combined_buffer_;
 
   base::WeakPtrFactory<BidirectionalStreamSpdyImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BidirectionalStreamSpdyImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_BIDIRECTIONAL_STREAM_SPDY_IMPL_H_