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

net/quic/bidirectional_stream_quic_impl.cc

Index: net/quic/bidirectional_stream_quic_impl.cc
diff --git a/net/quic/bidirectional_stream_quic_impl.cc b/net/quic/bidirectional_stream_quic_impl.cc
index b85997b67f2cd479e66dcf7191657bfd439fea2c..da6624023bb46ac5d7f55fdea2921188a491f03e 100644
--- a/net/quic/bidirectional_stream_quic_impl.cc
+++ b/net/quic/bidirectional_stream_quic_impl.cc
@@ -32,7 +32,7 @@ BidirectionalStreamQuicImpl::BidirectionalStreamQuicImpl(
       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);
@@ -47,12 +47,12 @@ BidirectionalStreamQuicImpl::~BidirectionalStreamQuicImpl() {
 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);
@@ -103,6 +103,16 @@ void BidirectionalStreamQuicImpl::SendData(const scoped_refptr<IOBuffer>& data,
   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,
@@ -126,6 +136,7 @@ void BidirectionalStreamQuicImpl::SendvData(
   QuicConnection::ScopedPacketBundler bundler(
       session_->connection(), QuicConnection::SEND_ACK_IF_PENDING);
   if (!has_sent_headers_) {
+    DCHECK(delay_headers_until_next_send_data_);
     SendRequestHeaders();
   }
 
@@ -238,7 +249,7 @@ void BidirectionalStreamQuicImpl::OnStreamReady(int 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();