[NaCl SDK] nacl_io: Add flow control the JavaScript pipes.

native_client_sdk/src/libraries/nacl_io/pipe/pipe_node.h

 // Copyright 2013 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 LIBRARIES_NACL_IO_PIPE_PIPE_NODE_H_
 #define LIBRARIES_NACL_IO_PIPE_PIPE_NODE_H_
 
 #include <map>
 #include <string>
 
 #include "nacl_io/pipe/pipe_event_emitter.h"
 #include "nacl_io/stream/stream_node.h"
 
 namespace nacl_io {
 
 class PipeNode : public StreamNode {
  public:
   explicit PipeNode(Filesystem* fs);
 
-  virtual EventEmitter* GetEventEmitter();
+  virtual PipeEventEmitter* GetEventEmitter();
   virtual Error Read(const HandleAttr& attr,
                      void* buf,
                      size_t count,
                      int* out_bytes);
   virtual Error Write(const HandleAttr& attr,
                       const void* buf,
                       size_t count,
                       int* out_bytes);
 
  protected:
   ScopedPipeEventEmitter pipe_;
 
   friend class KernelProxy;
   friend class StreamFs;
 };
 
 }  // namespace nacl_io
 
 #endif  // LIBRARIES_NACL_IO_PIPE_PIPE_NODE_H_