[Cronet] Add Hello World response to QuicTestServer and use it in bidirectional stream test.

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 190 matching lines @@
 }
 
 void CronetBidirectionalStream::ReadDataOnNetworkThread(
     scoped_refptr<net::WrappedIOBuffer> read_buffer,
     int buffer_size) {
   DCHECK(environment_->IsOnNetworkThread());
   DCHECK(read_buffer);
   DCHECK(!read_buffer_);
   if (read_state_ != WAITING_FOR_READ) {
     DLOG(ERROR) << "Unexpected Read Data in read_state " << WAITING_FOR_READ;
-    OnFailed(net::ERR_UNEXPECTED);
+    // Invoke OnFailed unless it is already invoked.
+    if (read_state_ != ERROR)
+      OnFailed(net::ERR_UNEXPECTED);
     return;
   }
   read_state_ = READING;
   read_buffer_ = read_buffer;
 
   int bytes_read = bidi_stream_->ReadData(read_buffer_.get(), buffer_size);
   // If IO is pending, wait for the BidirectionalStream to call OnDataRead.
   if (bytes_read == net::ERR_IO_PENDING)
     return;
 
   if (bytes_read < 0) {
     OnFailed(bytes_read);
     return;
   }
   OnDataRead(bytes_read);
 }
 
 void CronetBidirectionalStream::WriteDataOnNetworkThread(
     scoped_refptr<net::WrappedIOBuffer> write_buffer,
     int buffer_size,
     bool end_of_stream) {
   DCHECK(environment_->IsOnNetworkThread());
   DCHECK(write_buffer);
   DCHECK(!write_buffer_);
   if (write_state_ != WAITING_FOR_WRITE) {
     DLOG(ERROR) << "Unexpected Write Data in write_state " << write_state_;
-    OnFailed(net::ERR_UNEXPECTED);
+    // Invoke OnFailed unless it is already invoked.
+    if (write_state_ != ERROR)
+      OnFailed(net::ERR_UNEXPECTED);
     return;
   }
   write_state_ = WRITING;
   write_end_of_stream_ = end_of_stream;
 
   write_buffer_ = write_buffer;
   bidi_stream_->SendData(write_buffer_.get(), buffer_size, end_of_stream);
 }
 
 void CronetBidirectionalStream::CancelOnNetworkThread() {
@@ skipping 13 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