Move async_socket_io_handler.* from media/ to base/

media/audio/async_socket_io_handler.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 MEDIA_AUDIO_ASYNC_SOCKET_IO_HANDLER_H_
-#define MEDIA_AUDIO_ASYNC_SOCKET_IO_HANDLER_H_
-
-#include "base/message_loop/message_loop.h"
-#include "base/sync_socket.h"
-#include "base/threading/non_thread_safe.h"
-#include "media/base/media_export.h"
-
-namespace media {
-
-// The message loop callback interface is different based on platforms.
-#if defined(OS_WIN)
-typedef base::MessageLoopForIO::IOHandler MessageLoopIOHandler;
-#elif defined(OS_POSIX)
-typedef base::MessageLoopForIO::Watcher MessageLoopIOHandler;
-#endif
-
-// Extends the CancelableSyncSocket class to allow reading from a socket
-// asynchronously on a TYPE_IO message loop thread.  This makes it easy to share
-// a thread that uses a message loop (e.g. for IPC and other things) and not
-// require a separate thread to read from the socket.
-//
-// Example usage (also see the unit tests):
-//
-// class SocketReader {
-//  public:
-//   SocketReader(base::CancelableSyncSocket* socket)
-//       : socket_(socket), buffer_() {
-//     io_handler.Initialize(socket_->handle(),
-//                           base::Bind(&SocketReader::OnDataAvailable,
-//                                      base::Unretained(this));
-//   }
-//
-//   void AsyncRead() {
-//     CHECK(io_handler.Read(&buffer_[0], sizeof(buffer_)));
-//   }
-//
-//  private:
-//   void OnDataAvailable(int bytes_read) {
-//     if (ProcessData(&buffer_[0], bytes_read)) {
-//       // Issue another read.
-//       CHECK(io_handler.Read(&buffer_[0], sizeof(buffer_)));
-//     }
-//   }
-//
-//   media::AsyncSocketIoHandler io_handler;
-//   base::CancelableSyncSocket* socket_;
-//   char buffer_[kBufferSize];
-// };
-//
-class MEDIA_EXPORT AsyncSocketIoHandler
-    : public NON_EXPORTED_BASE(base::NonThreadSafe),
-      public NON_EXPORTED_BASE(MessageLoopIOHandler) {
- public:
-  AsyncSocketIoHandler();
-  virtual ~AsyncSocketIoHandler();
-
-  // Type definition for the callback. The parameter tells how many
-  // bytes were read and is 0 if an error occurred.
-  typedef base::Callback<void(int)> ReadCompleteCallback;
-
-  // Initializes the AsyncSocketIoHandler by hooking it up to the current
-  // thread's message loop (must be TYPE_IO), to do async reads from the socket
-  // on the current thread.  The |callback| will be invoked whenever a Read()
-  // has completed.
-  bool Initialize(base::SyncSocket::Handle socket,
-                  const ReadCompleteCallback& callback);
-
-  // Attempts to read from the socket.  The return value will be |false|
-  // if an error occurred and |true| if data was read or a pending read
-  // was issued.  Regardless of async or sync operation, the
-  // ReadCompleteCallback (see above) will be called when data is available.
-  bool Read(char* buffer, int buffer_len);
-
- private:
-#if defined(OS_WIN)
-  // Implementation of IOHandler on Windows.
-  virtual void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
-                             DWORD bytes_transfered,
-                             DWORD error) OVERRIDE;
-#elif defined(OS_POSIX)
-  // Implementation of base::MessageLoopForIO::Watcher.
-  virtual void OnFileCanWriteWithoutBlocking(int socket) OVERRIDE {}
-  virtual void OnFileCanReadWithoutBlocking(int socket) OVERRIDE;
-
-  void EnsureWatchingSocket();
-#endif
-
-  base::SyncSocket::Handle socket_;
-#if defined(OS_WIN)
-  base::MessageLoopForIO::IOContext* context_;
-  bool is_pending_;
-#elif defined(OS_POSIX)
-  base::MessageLoopForIO::FileDescriptorWatcher socket_watcher_;
-  // |pending_buffer_| and |pending_buffer_len_| are valid only between
-  // Read() and OnFileCanReadWithoutBlocking().
-  char* pending_buffer_;
-  int pending_buffer_len_;
-  // |true| iff the message loop is watching the socket for IO events.
-  bool is_watching_;
-#endif
-  ReadCompleteCallback read_complete_;
-
-  DISALLOW_COPY_AND_ASSIGN(AsyncSocketIoHandler);
-};
-
-}  // namespace media.
-
-#endif  // MEDIA_AUDIO_ASYNC_SOCKET_IO_HANDLER_H_