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diff --git a/Source/WebKit2/Platform/Region.h b/Source/WebKit2/Platform/Region.h
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+/*
+ * Copyright (C) 2010, 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef Region_h
+#define Region_h
+
+#include <WebCore/IntRect.h>
+#include <wtf/Vector.h>
+
+#include <vector>
+
+namespace WebKit {
+
+class Region {
+public:
+    Region();
+    Region(const WebCore::IntRect&);
+
+    WebCore::IntRect bounds() const { return m_bounds; }
+    bool isEmpty() const { return m_bounds.isEmpty(); }
+
+    Vector<WebCore::IntRect> rects() const;
+
+    void unite(const Region&);
+    void intersect(const Region&);
+    void subtract(const Region&);
+
+    void translate(const WebCore::IntSize&);
+
+#ifndef NDEBUG
+    void dump() const;
+#endif
+
+private:
+    struct Span {
+        Span(int y, size_t segmentIndex)
+            : y(y), segmentIndex(segmentIndex)
+        {
+        }
+
+        int y;
+        size_t segmentIndex;
+    };
+
+    class Shape {
+    public:
+        Shape();
+        Shape(const WebCore::IntRect&);
+
+        WebCore::IntRect bounds() const;
+        bool isEmpty() const { return m_spans.isEmpty(); }
+
+        typedef const Span* SpanIterator;
+        SpanIterator spans_begin() const;
+        SpanIterator spans_end() const;
+        
+        typedef const int* SegmentIterator;
+        SegmentIterator segments_begin(SpanIterator) const;
+        SegmentIterator segments_end(SpanIterator) const;
+
+        static Shape unionShapes(const Shape& shape1, const Shape& shape2);
+        static Shape intersectShapes(const Shape& shape1, const Shape& shape2);
+        static Shape subtractShapes(const Shape& shape1, const Shape& shape2);
+
+        void translate(const WebCore::IntSize&);
+        void swap(Shape&);
+
+#ifndef NDEBUG
+        void dump() const;
+#endif
+
+    private:
+        struct UnionOperation;
+        struct IntersectOperation;
+        struct SubtractOperation;
+        
+        template<typename Operation>
+        static Shape shapeOperation(const Shape& shape1, const Shape& shape2);
+
+        void appendSegment(int x);
+        void appendSpan(int y);
+        void appendSpan(int y, SegmentIterator begin, SegmentIterator end);
+        void appendSpans(const Shape&, SpanIterator begin, SpanIterator end);
+
+        bool canCoalesce(SegmentIterator begin, SegmentIterator end);
+
+        // FIXME: These vectors should have inline sizes. Figure out a good optimal value.
+        Vector<int> m_segments;
+        Vector<Span> m_spans;        
+    };
+
+    WebCore::IntRect m_bounds;
+    Shape m_shape;
+};
+
+static inline Region intersect(const Region& a, const Region& b)
+{
+    Region result(a);
+    result.intersect(b);
+
+    return result;
+}
+    
+static inline Region subtract(const Region& a, const Region& b)
+{
+    Region result(a);
+    result.subtract(b);
+
+    return result;
+}
+
+static inline Region translate(const Region& region, const WebCore::IntSize& offset)
+{
+    Region result(region);
+    result.translate(offset);
+
+    return result;
+}
+
+} // namespace WebKit
+
+#endif // Region_h