diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/utils/SkFrontBufferedStream.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/include/utils/SkFrontBufferedStream.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,35 @@
+/*
+ * 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.
+     *  @param minBufferSize Minimum size of buffer required.
+     *  @return An SkStream that can buffer at least minBufferSize, or
+     *      NULL on failure.
+     */
+    static SkStreamRewindable* Create(SkStream* stream, size_t minBufferSize);
+};