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diff --git a/WebCore/platform/image-decoders/ImageDecoder.h b/WebCore/platform/image-decoders/ImageDecoder.h
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+/*
+ * Copyright (C) 2006 Apple Computer, 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 COMPUTER, INC. ``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 COMPUTER, INC. OR
+ * 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 IMAGE_DECODER_H_
+#define IMAGE_DECODER_H_
+
+#include "IntRect.h"
+#include "ImageSource.h"
+#include "SharedBuffer.h"
+#include <wtf/Vector.h>
+
+namespace WebCore {
+
+typedef Vector<unsigned> RGBA32Array;
+
+// The RGBA32Buffer object represents the decoded image data in RGBA32 format.  This buffer is what all
+// decoders write a single frame into.  Frames are then instantiated for drawing by being handed this buffer.
+class RGBA32Buffer
+{
+public:
+    enum FrameStatus { FrameEmpty, FramePartial, FrameComplete };
+    enum FrameDisposalMethod {
+        // If you change the numeric values of these, make sure you audit all
+        // users, as some users may cast raw values to/from these constants.
+        DisposeNotSpecified = 0,       // Leave frame in framebuffer
+        DisposeKeep = 1,               // Leave frame in framebuffer
+        DisposeOverwriteBgcolor = 2,   // Clear frame to transparent
+        DisposeOverwritePrevious = 3,  // Clear frame to previous framebuffer contents
+    };
+
+    RGBA32Buffer() : m_height(0), m_status(FrameEmpty), m_duration(0),
+                     m_disposalMethod(DisposeNotSpecified), m_hasAlpha(false)
+    {} 
+
+    const RGBA32Array& bytes() const { return m_bytes; }
+    RGBA32Array& bytes() { return m_bytes; }
+    const IntRect& rect() const { return m_rect; }
+    unsigned height() const { return m_height; }
+    FrameStatus status() const { return m_status; }
+    unsigned duration() const { return m_duration; }
+    FrameDisposalMethod disposalMethod() const { return m_disposalMethod; }
+    bool hasAlpha() const { return m_hasAlpha; }
+
+    void setRect(const IntRect& r) { m_rect = r; }
+    void ensureHeight(unsigned rowIndex) { if (rowIndex > m_height) m_height = rowIndex; }
+    void setStatus(FrameStatus s) { m_status = s; }
+    void setDuration(unsigned duration) { m_duration = duration; }
+    void setDisposalMethod(FrameDisposalMethod method) { m_disposalMethod = method; }
+    void setHasAlpha(bool alpha) { m_hasAlpha = alpha; }
+
+    static void setRGBA(unsigned& pos, unsigned r, unsigned g, unsigned b, unsigned a)
+    {
+        // We store this data pre-multiplied.
+        if (a == 0)
+            pos = 0;
+        else {
+            if (a < 255) {
+                float alphaPercent = a / 255.0f;
+                r = static_cast<unsigned>(r * alphaPercent);
+                g = static_cast<unsigned>(g * alphaPercent);
+                b = static_cast<unsigned>(b * alphaPercent);
+            }
+            pos = (a << 24 | r << 16 | g << 8 | b);
+        }
+    }
+
+private:
+    RGBA32Array m_bytes;
+    IntRect m_rect;    // The rect of the original specified frame within the overall buffer.
+                       // This will always just be the entire buffer except for GIF frames
+                       // whose original rect was smaller than the overall image size.
+    unsigned m_height; // The height (the number of rows we've fully decoded).
+    FrameStatus m_status; // Whether or not this frame is completely finished decoding.
+    unsigned m_duration; // The animation delay.
+    FrameDisposalMethod m_disposalMethod; // What to do with this frame's data when initializing the next frame.
+    bool m_hasAlpha; // Whether or not any of the pixels in the buffer have transparency.
+};
+
+// The ImageDecoder class represents a base class for specific image format decoders
+// (e.g., GIF, JPG, PNG, ICO) to derive from.  All decoders decode into RGBA32 format
+// and the base class manages the RGBA32 frame cache.
+class ImageDecoder
+{
+public:
+    ImageDecoder() :m_sizeAvailable(false), m_failed(false) {}
+    virtual ~ImageDecoder() {}
+
+    // All specific decoder plugins must do something with the data they are given.
+    virtual void setData(SharedBuffer* data, bool allDataReceived) { m_data = data; }
+
+    // Whether or not the size information has been decoded yet.
+    virtual bool isSizeAvailable() const = 0;
+
+    // Requests the size.
+    virtual IntSize size() const { return m_size; }
+
+    // The total number of frames for the image.  Classes that support multiple frames
+    // will scan the image data for the answer if they need to (without necessarily
+    // decoding all of the individual frames).
+    virtual int frameCount() { return 1; }
+
+    // The number of repetitions to perform for an animation loop.
+    virtual int repetitionCount() const { return cAnimationNone; }
+
+    // Called to obtain the RGBA32Buffer full of decoded data for rendering.  The
+    // decoder plugin will decode as much of the frame as it can before handing
+    // back the buffer.
+    virtual RGBA32Buffer* frameBufferAtIndex(size_t index) = 0;
+
+    // Whether or not the underlying image format even supports alpha transparency.
+    virtual bool supportsAlpha() const { return true; }
+
+    bool failed() const { return m_failed; }
+    void setFailed() { m_failed = true; }
+
+protected:
+    RefPtr<SharedBuffer> m_data; // The encoded data.
+    Vector<RGBA32Buffer> m_frameBufferCache;
+    bool m_sizeAvailable;
+    mutable bool m_failed;
+    IntSize m_size;
+};
+
+}
+
+#endif