Move gif image decoder to SkCodec

third_party/WebKit/Source/platform/image-decoders/SegmentStream.h

+// Copyright (c) 2017 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 SegmentStream_h
+#define SegmentStream_h
+
+#include <algorithm>
+#include "platform/image-decoders/SegmentReader.h"
+#include "third_party/skia/include/core/SkStream.h"
+#include "wtf/RefPtr.h"
+
+namespace blink {
+
+class SegmentStream : public SkStream {
+ public:
+  SegmentStream();
+  virtual ~SegmentStream() {}
+
+  void setReader(SegmentReader*, bool allContentsReceived);
+  bool isCleared() const { return m_isCleared; }
+
+  // From SkStream:
+  size_t read(void* buffer, size_t) override;
+  size_t peek(void* buffer, size_t) const override;
+  bool isAtEnd() const override { return m_hasReadAllContents; }
+  bool rewind() override {
+    m_position = 0;
+    return true;
+  }
+  bool hasPosition() const override { return true; }
+  size_t getPosition() const override { return m_position; }
+  bool seek(size_t position) override {
+    position = std::min(position, m_reader->size());
+    m_position = position;
+
+    return true;
+  }
+  bool move(long offset) override;
+  bool hasLength() const override { return true; }
+  size_t getLength() const override { return m_reader->size(); }
+
+ private:
+  WTF::RefPtr<SegmentReader> m_reader;
+  size_t m_position;
+  bool m_hasReadAllContents;
+  bool m_isCleared;
+};
+
+}  // namespace blink
+
+#endif