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

components/cronet/ios/cronet_bidirectional_stream.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 "components/cronet/ios/cronet_bidirectional_stream.h"
 
 #include <memory>
 #include <string>
 #include <vector>
 
@@ skipping 95 matching lines @@
 
 void CronetBidirectionalStream::Destroy() {
   // Destroy could be called from any thread, including network thread (if
   // posting task to executor throws an exception), but is posted, so |this|
   // is valid until calling task is complete.
   environment_->PostToNetworkThread(
       FROM_HERE, base::Bind(&CronetBidirectionalStream::DestroyOnNetworkThread,
                             base::Unretained(this)));
 }
 
-void CronetBidirectionalStream::OnStreamReady() {
+void CronetBidirectionalStream::OnStreamReady(bool /*request_headers_sent*/) {
   DCHECK(environment_->IsOnNetworkThread());
   DCHECK(write_state_ == STARTED);
   write_state_ = WAITING_FOR_WRITE;
   if (write_end_of_stream_)
     write_state_ = WRITING_DONE;
   delegate_->OnStreamReady();
 }
 
 void CronetBidirectionalStream::OnHeadersReceived(
     const net::SpdyHeaderBlock& response_headers) {
@@ skipping 139 matching lines @@
 void CronetBidirectionalStream::MaybeOnSucceded() {
   DCHECK(environment_->IsOnNetworkThread());
   if (read_state_ == READING_DONE && write_state_ == WRITING_DONE) {
     read_state_ = write_state_ = SUCCESS;
     bidi_stream_.reset();
     delegate_->OnSucceeded();
   }
 }
 
 }  // namespace cronet