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

net/quic/bidirectional_stream_quic_impl.h

Index: net/quic/bidirectional_stream_quic_impl.h
diff --git a/net/quic/bidirectional_stream_quic_impl.h b/net/quic/bidirectional_stream_quic_impl.h
index e3ff775d8e4c71c52a1bf1bf537c28e497e88783..4ab004aca5a8a84a686a9092e274b69c0668c568 100644
--- a/net/quic/bidirectional_stream_quic_impl.h
+++ b/net/quic/bidirectional_stream_quic_impl.h
@@ -39,7 +39,7 @@ class NET_EXPORT_PRIVATE BidirectionalStreamQuicImpl
   // 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;
@@ -111,7 +111,9 @@ class NET_EXPORT_PRIVATE BidirectionalStreamQuicImpl
   // 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_;