diff -r 000000000000 -r 4f2f89ce4247 WebKit2/Shared/mac/UpdateChunk.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebKit2/Shared/mac/UpdateChunk.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2010 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 UpdateChunk_h
+#define UpdateChunk_h
+
+#include <WebCore/IntRect.h>
+#include <wtf/RetainPtr.h>
+
+namespace CoreIPC {
+    class ArgumentEncoder;
+    class ArgumentDecoder;
+}
+
+namespace WebKit {
+
+class UpdateChunk {
+public:
+    UpdateChunk();
+    UpdateChunk(const WebCore::IntRect&);
+    ~UpdateChunk();
+
+    uint8_t* data() { return m_data; }
+    const WebCore::IntRect& rect() const { return m_rect; }
+    bool isEmpty() const { return m_rect.isEmpty(); }
+
+    void encode(CoreIPC::ArgumentEncoder&) const;
+    static bool decode(CoreIPC::ArgumentDecoder&, UpdateChunk&);
+
+    RetainPtr<CGImageRef> createImage();
+
+private:
+    size_t size() const { return m_rect.width() * 4 * m_rect.height(); }
+
+    WebCore::IntRect m_rect;
+
+    // This needs to be mutable, because encoding an update chunk will hand over its memory to the target process.
+    mutable uint8_t* m_data;
+    size_t m_size;
+};
+
+} // namespace WebKit
+
+#endif // UpdateChunk_h