Reland r187230: Implement the Stream registry in content

content/browser/download/byte_stream.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_DOWNLOAD_BYTE_STREAM_H_
 #define CONTENT_BROWSER_DOWNLOAD_BYTE_STREAM_H_
 
 #include <set>
 #include <utility>
 #include <deque>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "net/base/io_buffer.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace content {
 
+// TODO(zork): Move this class out of content/browser/download
+// crbug.com/180833
+//
 // A byte stream is a pipe to transfer bytes between a source and a
 // sink, which may be on different threads.  It is intended to be the
 // only connection between source and sink; they need have no
 // direct awareness of each other aside from the byte stream.  The source and
 // the sink have different interfaces to a byte stream, |ByteStreamWriter|
 // and |ByteStreamReader|.  A pair of connected interfaces is generated by
 // calling |CreateByteStream|.
 //
 // The source adds bytes to the bytestream via |ByteStreamWriter::Write|
 // and the sink retrieves bytes already written via |ByteStreamReader::Read|.
@@ skipping 153 matching lines @@
 CONTENT_EXPORT void CreateByteStream(
     scoped_refptr<base::SequencedTaskRunner> input_task_runner,
     scoped_refptr<base::SequencedTaskRunner> output_task_runner,
     size_t buffer_size,
     scoped_ptr<ByteStreamWriter>* input,
     scoped_ptr<ByteStreamReader>* output);
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_BYTE_STREAM_H_