Force image-decoding before resolving createImageBitmap promise

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 70e44f107e18ca2162b7060aabdb147d64a335cb..66af5e6fe21da6105b671bda4f486279dafe1e8f 100644
--- a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
+++ b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
@@ -135,7 +135,13 @@ static PassRefPtr<StaticBitmapImage> cropImage(Image* image, const IntRect& crop
     if (cropRect == srcRect) {
         if (flipY)
             return StaticBitmapImage::create(flipSkImageVertically(skiaImage->newSubset(srcRect), premultiplyAlpha ? PremultiplyAlpha : DontPremultiplyAlpha));
-        return StaticBitmapImage::create(adoptRef(skiaImage->newSubset(srcRect)));
+        SkImage* croppedSkImage = skiaImage->newSubset(srcRect);
+        if (cropRect == imgRect) {
+            SkImageInfo info = SkImageInfo::MakeN32(image->width(), image->height(), premultiplyAlpha ? kPremul_SkAlphaType : kUnpremul_SkAlphaType);
+            OwnPtr<uint8_t[]> imagePixels = copySkImageData(croppedSkImage, info);

[Justin Novosad, 2016/03/17 21:27:21]

Making a full copy, only to discard it after is wasteful. I understand that the
skia API is too opaque to trigger an immediate decode by any other means, but I
think you could read just a 1x1 pixel subregion.

+
+        }
+        return StaticBitmapImage::create(adoptRef(croppedSkImage));
     }
 
     RefPtr<SkSurface> surface = adoptRef(SkSurface::NewRasterN32Premul(cropRect.width(), cropRect.height()));