Eliminate copies of encoded image data

third_party/WebKit/Source/platform/image-decoders/DataSegmentReader.cpp

+// Copyright 2016 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.
+
+#include "DataSegmentReader.h"
+
+namespace blink {
+
+DataSegmentReader::DataSegmentReader(PassRefPtr<SkData> data)
+: m_data(skia::AdoptRef(data.leakRef())) {}
+
+size_t DataSegmentReader::size() const
+{
+    return m_data->size();
+}
+
+size_t DataSegmentReader::getSomeData(const char*& data, size_t position) const
+{
+    if (position >= m_data->size())
+        return 0;
+
+    data = reinterpret_cast<const char*>(m_data->bytes() + position);
+    return m_data->size() - position;
+}
+
+PassRefPtr<SkData> DataSegmentReader::getAsSkData() const
+{
+    return m_data.get();
+}
+
+} // namespace blink
+