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

net/quic/bidirectional_stream_quic_impl.cc

 // 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.
 
 #include "net/quic/bidirectional_stream_quic_impl.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/timer/timer.h"
@@ skipping 14 matching lines @@
       delegate_(nullptr),
       response_status_(OK),
       negotiated_protocol_(kProtoUnknown),
       read_buffer_len_(0),
       headers_bytes_received_(0),
       headers_bytes_sent_(0),
       closed_stream_received_bytes_(0),
       closed_stream_sent_bytes_(0),
       has_sent_headers_(false),
       has_received_headers_(false),
-      disable_auto_flush_(false),
+      delay_headers_until_next_send_data_(false),
       weak_factory_(this) {
   DCHECK(session_);
   session_->AddObserver(this);
 }
 
 BidirectionalStreamQuicImpl::~BidirectionalStreamQuicImpl() {
   Cancel();
   if (session_)
     session_->RemoveObserver(this);
 }
 
 void BidirectionalStreamQuicImpl::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 */) {
   DCHECK(!stream_);
 
-  disable_auto_flush_ = disable_auto_flush;
+  delay_headers_until_next_send_data_ = delay_headers_until_next_send_data;
   if (!session_) {
     NotifyError(was_handshake_confirmed_ ? ERR_QUIC_PROTOCOL_ERROR
                                          : ERR_QUIC_HANDSHAKE_FAILED);
     return;
   }
 
   delegate_ = delegate;
   request_info_ = request_info;
 
   int rv = stream_request_.StartRequest(
@@ skipping 30 matching lines @@
   read_buffer_len_ = buffer_len;
   return ERR_IO_PENDING;
 }
 
 void BidirectionalStreamQuicImpl::SendData(const scoped_refptr<IOBuffer>& data,
                                            int length,
                                            bool end_stream) {
   DCHECK(stream_);
   DCHECK(length > 0 || (length == 0 && end_stream));
 
+  std::unique_ptr<QuicConnection::ScopedPacketBundler> bundler;
+  if (!has_sent_headers_) {
+    DCHECK(delay_headers_until_next_send_data_);
+    // Creates a bundler only if there are headers to be sent along with the
+    // single data buffer.
+    bundler.reset(new QuicConnection::ScopedPacketBundler(
+        session_->connection(), QuicConnection::SEND_ACK_IF_PENDING));
+    SendRequestHeaders();
+  }
+
   base::StringPiece string_data(data->data(), length);
   int rv = stream_->WriteStreamData(
       string_data, end_stream,
       base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
                  weak_factory_.GetWeakPtr()));
   DCHECK(rv == OK || rv == ERR_IO_PENDING);
   if (rv == OK) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
                               weak_factory_.GetWeakPtr(), OK));
   }
 }
 
 void BidirectionalStreamQuicImpl::SendvData(
     const std::vector<scoped_refptr<IOBuffer>>& buffers,
     const std::vector<int>& lengths,
     bool end_stream) {
   DCHECK(stream_);
   DCHECK_EQ(buffers.size(), lengths.size());
 
   QuicConnection::ScopedPacketBundler bundler(
       session_->connection(), QuicConnection::SEND_ACK_IF_PENDING);
   if (!has_sent_headers_) {
+    DCHECK(delay_headers_until_next_send_data_);
     SendRequestHeaders();
   }
 
   int rv = stream_->WritevStreamData(
       buffers, lengths, end_stream,
       base::Bind(&BidirectionalStreamQuicImpl::OnSendDataComplete,
                  weak_factory_.GetWeakPtr()));
 
   DCHECK(rv == OK || rv == ERR_IO_PENDING);
   if (rv == OK) {
@@ skipping 92 matching lines @@
   DCHECK_NE(OK, error);
   session_.reset();
   NotifyError(error);
 }
 
 void BidirectionalStreamQuicImpl::OnStreamReady(int rv) {
   DCHECK_NE(ERR_IO_PENDING, rv);
   DCHECK(rv == OK || !stream_);
   if (rv == OK) {
     stream_->SetDelegate(this);
-    if (!disable_auto_flush_) {
+    if (!delay_headers_until_next_send_data_) {
       SendRequestHeaders();
     }
     delegate_->OnStreamReady();
   } else {
     NotifyError(rv);
   }
 }
 
 void BidirectionalStreamQuicImpl::OnSendDataComplete(int rv) {
   DCHECK(rv == OK || !stream_);
@@ skipping 35 matching lines @@
 void BidirectionalStreamQuicImpl::ResetStream() {
   if (!stream_)
     return;
   closed_stream_received_bytes_ = stream_->stream_bytes_read();
   closed_stream_sent_bytes_ = stream_->stream_bytes_written();
   stream_->SetDelegate(nullptr);
   stream_ = nullptr;
 }
 
 }  // namespace net