Make SkStream *not* ref counted.

include/utils/SkFrontBufferedStream.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTypes.h"
 
 class SkStream;
 class SkStreamRewindable;
 
 /**
  *  Specialized stream that buffers the first X bytes of a stream,
  *  where X is passed in by the user. Note that unlike some buffered
  *  stream APIs, once more bytes than can fit in the buffer are read,
  *  no more buffering is done. This stream is designed for a use case
  *  where the caller knows that rewind will only be called from within
  *  X bytes (inclusive), and the wrapped stream is not necessarily
  *  able to rewind at all.
  */
 class SkFrontBufferedStream {
 public:
     /**
      *  Creates a new stream that wraps and buffers an SkStream.
      *  @param stream SkStream to buffer. If stream is NULL, NULL is
      *      returned. When this call succeeds (i.e. returns non NULL),
      *      SkFrontBufferedStream is expected to be the only owner of
-     *      stream, so it should be unreffed and no longer used directly.
+     *      stream, so it should no be longer used directly.
+     *      SkFrontBufferedStream will delete stream upon deletion.
      *  @param minBufferSize Minimum size of buffer required.
      *  @return An SkStream that can buffer at least minBufferSize, or
-     *      NULL on failure.
+     *      NULL on failure. The caller is required to delete when finished with
+     *      this object.
      */
     static SkStreamRewindable* Create(SkStream* stream, size_t minBufferSize);
 };