Add animation support for WebP images

Source/core/platform/image-decoders/webp/WEBPImageDecoder.h

Index: Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
diff --git a/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h b/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
index 6cb469c18012ff63a1e96afe673c3d2800fc6427..70355b652b983cad0b9c8df76e9b799f0d8e17b6 100644
--- a/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
+++ b/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
@@ -32,9 +32,13 @@
 #include "core/platform/image-decoders/ImageDecoder.h"
 
 #include "webp/decode.h"
-#if USE(QCMSLIB) && (WEBP_DECODER_ABI_VERSION > 0x200)
+#if (WEBP_DECODER_ABI_VERSION > 0x200)
+#include "webp/demux.h"
+#define WEBP_ICC_ANIMATION_SUPPORT
+#if USE(QCMSLIB)
 #define QCMS_WEBP_COLOR_CORRECTION
 #endif
+#endif
 
 namespace WebCore {
 
@@ -45,29 +49,58 @@ public:
 
     virtual String filenameExtension() const { return "webp"; }
     virtual bool isSizeAvailable();
+    virtual size_t frameCount();
     virtual ImageFrame* frameBufferAtIndex(size_t index);
+#ifdef WEBP_ICC_ANIMATION_SUPPORT
+    virtual void setData(SharedBuffer* data, bool allDataReceived);
+    virtual int repetitionCount() const { return m_repetitionCount; }
+    virtual void clearFrameBufferCache(size_t clearBeforeFrame);
+#endif
 
 private:
-    bool decode(bool onlySize);
+    bool decode(const uint8_t* dataBytes, size_t dataSize, bool onlySize, size_t frameIndex);
 
     WebPIDecoder* m_decoder;
     WebPDecBuffer m_decoderBuffer;
-    bool m_hasAlpha;
     int m_formatFlags;
 
 #ifdef QCMS_WEBP_COLOR_CORRECTION
     qcms_transform* colorTransform() const { return m_transform; }
     void createColorTransform(const char* data, size_t);
-    void readColorProfile(const uint8_t* data, size_t);
-    void applyColorProfile(const uint8_t* data, size_t, ImageFrame&);
+    void readColorProfile();
 
     bool m_haveReadProfile;
     qcms_transform* m_transform;
+#endif
+
+#ifdef WEBP_ICC_ANIMATION_SUPPORT
+    // Recreates demux object when new data is available, and sets canvas size, format flags,

[Noel Gordon, 2013/05/03 18:15:46]

You're trying to tell me again what I can read from the code :)  And it would be
a very long comment if you itemized all that this involved routine does, and it
returns false as times.  Maybe you could discuss it all in the change decription
if there's something important we need to know about why this routine exists.

[urvang (Google), 2013/05/03 21:55:20]

I like to err on the side of explicit commenting in the code; Blink seems to err
the other way ;)

Anyway, removed the comment.

[Noel Gordon, 2013/05/04 17:23:43]

Comments don't help if they contain factual errors, which they did in this case.
 Read the references about comments at the bottom of this page:
http://www.chromium.org/blink/coding-style

I saw no update to the change description.  You could add something explicit
there, discussing why this routine exists along with any other important aspects
of this change you want to comment about ...

Some recent change description examples 

https://chromium.googlesource.com/chromium/blink/+/eb044f7ad5a3561119266652f1...
https://chromium.googlesource.com/chromium/blink/+/c385eb957f7bbb7d462d47db44...

to get you going.

[urvang (Google), 2013/05/07 06:53:44]

I added notes about the major methods added in the change description.

+    // animation properties etc as appropriate. Returns true on success. On
+    // failure, this will mark the image as failed.
+    bool updateDemuxer();
+    // Called to initialize the frame buffer at the given index based on
+    // the previous frame's disposal method. Returns true on success. On
+    // failure, this will mark the image as failed.

[Noel Gordon, 2013/05/03 18:15:46]

s/this will mark/marks/

[urvang (Google), 2013/05/03 21:55:20]

Done.

+    bool initFrameBuffer(const WebPIterator&, size_t frameIndex);
+    // Apply color profile, and perform necessary post-processing for frame disposal.

[Noel Gordon, 2013/05/03 18:15:46]

applyPostProcessing() tells me that some post processing is needed.  But we
don't always apply a color profile, or do frame disposal. Perhaps let the
function name stand alone on its own merits, no comment needed.

[urvang (Google), 2013/05/03 21:55:20]

Done.

+    void applyPostProcessing(size_t frameIndex);
+
+    // Number of rows decoded and post-processed so far in the current frame. It

[Noel Gordon, 2013/05/03 18:15:46]

I'd accept the first sentence only.  Move this down, and group it with the other
member vars.

[urvang (Google), 2013/05/03 21:55:20]

Done.
Not sure what you meant. Do you want to to bring all member vars down (after all
the method declarations)? I feel that this way is better maybe, to keep the
number all #ifdefs under control :)

[Noel Gordon, 2013/05/04 17:23:43]

Apologies. I meant group the members of this #ifdef group, like so

#ifdef WEBP_ICC_ANIMATION_SUPPORT
    ...
    void applyPostProcessing(size_t frameIndex);

    WebPDemuxer* m_demux;
    WebPDemuxState m_demuxState;
    bool m_haveAlreadyParsedThisData;
    bool m_haveReadAnimParams;
    int m_repetitionCount;
    int m_decodedHeight;
#endif

[urvang (Google), 2013/05/07 06:53:44]

Done.

+    // is used by applyPostProcessing() to decode and post-process incrementally.
     int m_decodedHeight;
+
+    bool m_haveAlreadyParsedThisData;
+    WebPDemuxer* m_demux;
+    WebPDemuxState m_demuxState;
+
+    bool m_haveReadAnimParams;
+    int m_repetitionCount;
 #else
-    void applyColorProfile(const uint8_t*, size_t, ImageFrame&) { };
+    void applyPostProcessing(size_t) { };
 #endif
+
     void clear();
+    void clearDecoder();
 };
 
 } // namespace WebCore