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..43aef5b8c295b9b34c440ad02f9e1da93974852e 100644
--- a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
+++ b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
@@ -135,7 +135,14 @@ 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) {
+            // Call readPixels to trigger image decoding. Only read 1*1 subregion to be efficient.
+            SkImageInfo info = SkImageInfo::MakeN32(1, 1, premultiplyAlpha ? kPremul_SkAlphaType : kUnpremul_SkAlphaType);
+            OwnPtr<uint8_t[]> imagePixels = adoptArrayPtr(new uint8_t[info.bytesPerPixel()]);
+            croppedSkImage->readPixels(info, imagePixels.get(), info.bytesPerPixel(), 0, 0);
+        }
+        return StaticBitmapImage::create(adoptRef(croppedSkImage));
     }
 
     RefPtr<SkSurface> surface = adoptRef(SkSurface::NewRasterN32Premul(cropRect.width(), cropRect.height()));