Use ConnectionErrorObserver, not callbacks, for error handling.

blimp/net/blimp_message_output_buffer.h

 // Copyright 2015 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.
 
 #ifndef BLIMP_NET_BLIMP_MESSAGE_OUTPUT_BUFFER_H_
 #define BLIMP_NET_BLIMP_MESSAGE_OUTPUT_BUFFER_H_
 
 #include <stdint.h>
 
 #include <list>
@@ skipping 53 matching lines @@
     const std::unique_ptr<BlimpMessage> message;
     const net::CompletionCallback callback;
   };
 
   typedef std::list<std::unique_ptr<BufferEntry>> MessageBuffer;
 
   // Writes the next message in the buffer if an output processor is attached
   // and the buffer contains a message.
   void WriteNextMessageIfReady();
 
-  // Receives the completion status of a write operation.
+  // Called after a successful write.
   void OnWriteComplete(int result);
 
   BlimpMessageProcessor* output_processor_ = nullptr;
   net::CancelableCompletionCallback write_complete_cb_;
 
   // Maximum serialized footprint of buffered messages.
   int max_buffer_size_bytes_;
 
   // Serialized footprint of the messages contained in the write and ack
   // buffers.
   int current_buffer_size_bytes_ = 0;
 
   // The ID used by the last outgoing message.
   int64_t prev_message_id_ = 0;
 
   // List of unsent messages.
   MessageBuffer write_buffer_;
 
   // List of messages that are sent and awaiting acknowledgment.
   // The messages in |ack_buffer_| are contiguous with the messages in
   // |write_buffer_|.
   MessageBuffer ack_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(BlimpMessageOutputBuffer);
 };
 
 }  // namespace blimp
 
 #endif  // BLIMP_NET_BLIMP_MESSAGE_OUTPUT_BUFFER_H_