Change code path for structured cloning ImageBitmap

third_party/WebKit/Source/core/frame/ImageBitmap.cpp

Index: third_party/WebKit/Source/core/frame/ImageBitmap.cpp
diff --git a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
index 7c0de1e9e10b593f496e058d70579b981bd201f8..43712ac7eae04c778685a372ea827e0843f35a31 100644
--- a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
+++ b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
@@ -258,8 +258,20 @@ ImageBitmap::ImageBitmap(HTMLCanvasElement* canvas, const IntRect& cropRect, con
     m_image->setPremultiplied(premultiplyAlpha);
 }
 
-// The last two parameters are used for structure-cloning.
-ImageBitmap::ImageBitmap(ImageData* data, const IntRect& cropRect, const ImageBitmapOptions& options, const bool& isImageDataPremultiplied, const bool& isImageDataOriginClean)
+// This constructor is called by structured-cloning an ImageBitmap.
+// isImageBitmapPremultiplied indicates whether the original ImageBitmap is premultiplied or not.

[jbroman, 2016/06/28 18:50:22]

Comments like this normally go in the header, since they describe how to call
the function correctly. I'd also specify in the comment that it specifies
whether the provided data contains premultiplied or unpremultiplied pixel data.

[xidachen, 2016/06/29 12:58:35]

Done.

+// isImageBitmapOriginClean indicates whether the original ImageBitmap is origin clean or not.
+ImageBitmap::ImageBitmap(std::unique_ptr<uint8_t[]> data, uint32_t width, uint32_t height, bool isImageBitmapPremultiplied, bool isImageBitmapOriginClean)
+{
+    SkImageInfo info = SkImageInfo::Make(width, height, kBGRA_8888_SkColorType, isImageBitmapPremultiplied ? kPremul_SkAlphaType : kUnpremul_SkAlphaType);
+    swizzleImageData(data.get(), height, info.bytesPerPixel() * width, false);

[jbroman, 2016/06/28 18:50:22]

What's the purpose of this swizzling? Why aren't we serializing data in the most
convenient format to read it?

[xidachen, 2016/06/29 12:58:35]

Done.

+    m_image = StaticBitmapImage::create(fromSkSp(SkImage::MakeRasterCopy(SkPixmap(info, data.get(), info.bytesPerPixel() * width))));
+    swizzleImageData(data.get(), height, info.bytesPerPixel() * width, false);

[jbroman, 2016/06/28 18:50:22]

Why unswizzle the data when we're about to delete it anyhow?

[xidachen, 2016/06/29 12:58:35]

Done.

+    m_image->setPremultiplied(isImageBitmapPremultiplied);
+    m_image->setOriginClean(isImageBitmapOriginClean);
+}
+
+ImageBitmap::ImageBitmap(ImageData* data, const IntRect& cropRect, const ImageBitmapOptions& options)
 {
     bool flipY;
     bool premultiplyAlpha;
@@ -273,11 +285,7 @@ ImageBitmap::ImageBitmap(ImageData* data, const IntRect& cropRect, const ImageBi
         int dstHeight = cropRect.height();
         // TODO (xidachen): skia doesn't support SkImage::NewRasterCopy from a kRGBA color type.
         // For now, we swap R and B channel and uses kBGRA color type.
-        SkImageInfo info;
-        if (!isImageDataPremultiplied)
-            info = SkImageInfo::Make(cropRect.width(), dstHeight, kBGRA_8888_SkColorType, kUnpremul_SkAlphaType);
-        else
-            info = SkImageInfo::Make(cropRect.width(), dstHeight, kBGRA_8888_SkColorType, kPremul_SkAlphaType);
+        SkImageInfo info = SkImageInfo::Make(cropRect.width(), dstHeight, kBGRA_8888_SkColorType, kUnpremul_SkAlphaType);
         int srcPixelBytesPerRow = info.bytesPerPixel() * data->size().width();
         int dstPixelBytesPerRow = info.bytesPerPixel() * cropRect.width();
         if (cropRect == IntRect(IntPoint(), data->size())) {
@@ -317,7 +325,6 @@ ImageBitmap::ImageBitmap(ImageData* data, const IntRect& cropRect, const ImageBi
             m_image = StaticBitmapImage::create(newSkImageFromRaster(info, std::move(copiedDataBuffer), dstPixelBytesPerRow));
         }
         m_image->setPremultiplied(premultiplyAlpha);
-        m_image->setOriginClean(isImageDataOriginClean);
         return;
     }
 
@@ -405,10 +412,10 @@ ImageBitmap* ImageBitmap::create(HTMLCanvasElement* canvas, const IntRect& cropR
     return new ImageBitmap(canvas, normalizedCropRect, options);
 }
 
-ImageBitmap* ImageBitmap::create(ImageData* data, const IntRect& cropRect, const ImageBitmapOptions& options, const bool& isImageDataPremultiplied, const bool& isImageDataOriginClean)
+ImageBitmap* ImageBitmap::create(ImageData* data, const IntRect& cropRect, const ImageBitmapOptions& options)
 {
     IntRect normalizedCropRect = normalizeRect(cropRect);
-    return new ImageBitmap(data, normalizedCropRect, options, isImageDataPremultiplied, isImageDataOriginClean);
+    return new ImageBitmap(data, normalizedCropRect, options);
 }
 
 ImageBitmap* ImageBitmap::create(ImageBitmap* bitmap, const IntRect& cropRect, const ImageBitmapOptions& options)
@@ -433,6 +440,11 @@ ImageBitmap* ImageBitmap::create(WebExternalTextureMailbox& mailbox)
     return new ImageBitmap(mailbox);
 }
 
+ImageBitmap* ImageBitmap::create(std::unique_ptr<uint8_t[]> data, uint32_t width, uint32_t height, bool isImageBitmapPremultiplied, bool isImageBitmapOriginClean)
+{
+    return new ImageBitmap(std::move(data), width, height, isImageBitmapPremultiplied, isImageBitmapOriginClean);
+}
+
 void ImageBitmap::close()
 {
     if (!m_image || m_isNeutered)