Revert of Eliminate copies of encoded image data

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

Index: third_party/WebKit/Source/platform/image-decoders/SegmentReader.cpp
diff --git a/third_party/WebKit/Source/platform/image-decoders/SegmentReader.cpp b/third_party/WebKit/Source/platform/image-decoders/SegmentReader.cpp
deleted file mode 100644
index e4129528c1481fa0993a7f1d477f5aa4b876897c..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/platform/image-decoders/SegmentReader.cpp
+++ /dev/null
@@ -1,182 +0,0 @@
-// 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 "platform/image-decoders/SegmentReader.h"
-
-#include "platform/SharedBuffer.h"
-#include "third_party/skia/include/core/SkData.h"
-#include "wtf/Assertions.h"
-#include "wtf/Noncopyable.h"
-#include "wtf/PassRefPtr.h"
-#include "wtf/RefPtr.h"
-
-namespace blink {
-
-// SharedBufferSegmentReader ---------------------------------------------------
-
-// Interface for ImageDecoder to read a SharedBuffer.
-class SharedBufferSegmentReader final : public SegmentReader {
-    WTF_MAKE_NONCOPYABLE(SharedBufferSegmentReader);
-public:
-    SharedBufferSegmentReader(PassRefPtr<SharedBuffer>);
-    size_t size() const override;
-    size_t getSomeData(const char*& data, size_t position) const override;
-    PassRefPtr<SkData> getAsSkData() const override;
-private:
-    RefPtr<SharedBuffer> m_sharedBuffer;
-};
-
-SharedBufferSegmentReader::SharedBufferSegmentReader(PassRefPtr<SharedBuffer> buffer)
-    : m_sharedBuffer(buffer) {}
-
-size_t SharedBufferSegmentReader::size() const
-{
-    return m_sharedBuffer->size();
-}
-
-size_t SharedBufferSegmentReader::getSomeData(const char*& data, size_t position) const
-{
-    return m_sharedBuffer->getSomeData(data, position);
-}
-
-PassRefPtr<SkData> SharedBufferSegmentReader::getAsSkData() const
-{
-    return m_sharedBuffer->getAsSkData();
-}
-
-// DataSegmentReader -----------------------------------------------------------
-
-// Interface for ImageDecoder to read an SkData.
-class DataSegmentReader final : public SegmentReader {
-    WTF_MAKE_NONCOPYABLE(DataSegmentReader);
-public:
-    DataSegmentReader(PassRefPtr<SkData>);
-    size_t size() const override;
-    size_t getSomeData(const char*& data, size_t position) const override;
-    PassRefPtr<SkData> getAsSkData() const override;
-private:
-    RefPtr<SkData> m_data;
-};
-
-DataSegmentReader::DataSegmentReader(PassRefPtr<SkData> data)
-    : m_data(data) {}
-
-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();
-}
-
-// ROBufferSegmentReader -------------------------------------------------------
-
-class ROBufferSegmentReader final : public SegmentReader {
-    WTF_MAKE_NONCOPYABLE(ROBufferSegmentReader);
-public:
-    ROBufferSegmentReader(PassRefPtr<SkROBuffer>);
-
-    size_t size() const override;
-    size_t getSomeData(const char*& data, size_t position) const override;
-    PassRefPtr<SkData> getAsSkData() const override;
-
-private:
-    RefPtr<SkROBuffer> m_roBuffer;
-};
-
-ROBufferSegmentReader::ROBufferSegmentReader(PassRefPtr<SkROBuffer> buffer)
-    : m_roBuffer(buffer)
-    {}
-
-size_t ROBufferSegmentReader::size() const
-{
-    return m_roBuffer ? m_roBuffer->size() : 0;
-}
-
-size_t ROBufferSegmentReader::getSomeData(const char*& data, size_t position) const
-{
-    if (!m_roBuffer)
-        return 0;
-
-    SkROBuffer::Iter iter(m_roBuffer.get());
-    for (size_t sizeOfBlock = iter.size(), positionOfBlock = 0; sizeOfBlock != 0; positionOfBlock += sizeOfBlock, sizeOfBlock = iter.size()) {
-        ASSERT(positionOfBlock <= position);
-
-        if (positionOfBlock + sizeOfBlock > position) {
-            // |position| is in this block.
-            const size_t positionInBlock = position - positionOfBlock;
-            data = static_cast<const char*>(iter.data()) + positionInBlock;
-            return sizeOfBlock - positionInBlock;
-        }
-
-        // Move to next block.
-        if (!iter.next()) {
-            return 0;
-        }
-    }
-
-    return 0;
-}
-
-static void unrefROBuffer(const void* ptr, void* context)
-{
-    static_cast<SkROBuffer*>(context)->unref();
-}
-
-PassRefPtr<SkData> ROBufferSegmentReader::getAsSkData() const
-{
-    if (!m_roBuffer)
-        return nullptr;
-
-    // Check to see if the data is already contiguous.
-    SkROBuffer::Iter iter(m_roBuffer.get());
-    const bool multipleBlocks = iter.next();
-    iter.reset(m_roBuffer.get());
-
-    if (!multipleBlocks) {
-        // Contiguous data. No need to copy.
-        m_roBuffer->ref();
-        return adoptRef(SkData::NewWithProc(iter.data(), iter.size(), &unrefROBuffer, m_roBuffer.get()));
-    }
-
-    RefPtr<SkData> data = adoptRef(SkData::NewUninitialized(m_roBuffer->size()));
-    char* dst = static_cast<char*>(data->writable_data());
-    do {
-        size_t size = iter.size();
-        memcpy(dst, iter.data(), size);
-        dst += size;
-    } while (iter.next());
-    return data.release();
-}
-
-// SegmentReader ---------------------------------------------------------------
-
-PassRefPtr<SegmentReader> SegmentReader::createFromSharedBuffer(PassRefPtr<SharedBuffer> buffer)
-{
-    return adoptRef(new SharedBufferSegmentReader(buffer));
-}
-
-PassRefPtr<SegmentReader> SegmentReader::createFromSkData(PassRefPtr<SkData> data)
-{
-    return adoptRef(new DataSegmentReader(data));
-}
-
-PassRefPtr<SegmentReader> SegmentReader::createFromSkROBuffer(PassRefPtr<SkROBuffer> buffer)
-{
-    return adoptRef(new ROBufferSegmentReader(buffer));
-}
-
-} // namespace blink
-