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

net/spdy/bidirectional_stream_spdy_impl.h

Index: net/spdy/bidirectional_stream_spdy_impl.h
diff --git a/net/spdy/bidirectional_stream_spdy_impl.h b/net/spdy/bidirectional_stream_spdy_impl.h
index 2ddd4f8fb1029846b3a12d86d17e87e2a1354403..06d0d351f1be3d8b7672de34ed3dd956696aa0fc 100644
--- a/net/spdy/bidirectional_stream_spdy_impl.h
+++ b/net/spdy/bidirectional_stream_spdy_impl.h
@@ -42,9 +42,10 @@ class NET_EXPORT_PRIVATE BidirectionalStreamSpdyImpl
   // BidirectionalStreamImpl implementation:
   void Start(const BidirectionalStreamRequestInfo* request_info,
              const BoundNetLog& net_log,
-             bool disable_auto_flush,
+             bool send_request_headers_automatically,
              BidirectionalStreamImpl::Delegate* delegate,
              std::unique_ptr<base::Timer> timer) override;
+  void SendRequestHeaders() override;
   int ReadData(IOBuffer* buf, int buf_len) override;
   void SendData(const scoped_refptr<IOBuffer>& data,
                 int length,
@@ -67,7 +68,7 @@ class NET_EXPORT_PRIVATE BidirectionalStreamSpdyImpl
   void OnClose(int status) override;
 
  private:
-  void SendRequestHeaders();
+  int SendRequestHeadersHelper();
   void OnStreamInitialized(int rv);
   void ScheduleBufferedRead();
   void DoBufferedRead();
@@ -100,10 +101,8 @@ class NET_EXPORT_PRIVATE BidirectionalStreamSpdyImpl
   // 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_;