Use SkCanvas transform instead of flipSkImageVertically

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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/ImageBitmap.h"
 
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLVideoElement.h"
 #include "core/html/ImageData.h"
 #include "platform/graphics/skia/SkiaUtils.h"
@@ skipping 237 matching lines @@
         return nullptr;
     if (srcRect.isEmpty())
         return StaticBitmapImage::create(fromSkSp(surface->makeImageSnapshot()));
 
     SkScalar dstLeft = std::min(0, -parsedOptions.cropRect.x());
     SkScalar dstTop = std::min(0, -parsedOptions.cropRect.y());
     if (parsedOptions.cropRect.x() < 0)
         dstLeft = -parsedOptions.cropRect.x();
     if (parsedOptions.cropRect.y() < 0)
         dstTop = -parsedOptions.cropRect.y();
+    if (parsedOptions.flipY) {
+        surface->getCanvas()->translate(0, surface->height());
+        surface->getCanvas()->scale(1, -1);
+    }
     if (parsedOptions.shouldScaleInput) {
         SkRect drawDstRect = SkRect::MakeXYWH(dstLeft, dstTop, parsedOptions.resizeWidth, parsedOptions.resizeHeight);
         SkPaint paint;
         paint.setFilterQuality(parsedOptions.resizeQuality);
         surface->getCanvas()->drawImageRect(skiaImage.get(), drawDstRect, &paint);
     } else {
         surface->getCanvas()->drawImage(skiaImage.get(), dstLeft, dstTop);
     }
     skiaImage = fromSkSp(surface->makeImageSnapshot());
-    if (parsedOptions.flipY)
-        skiaImage = flipSkImageVertically(skiaImage.get(), PremultiplyAlpha);
 
     if (parsedOptions.premultiplyAlpha) {
         if (imageFormat == PremultiplyAlpha)
             return StaticBitmapImage::create(unPremulSkImageToPremul(skiaImage.get()));
         return StaticBitmapImage::create(skiaImage.release());
     }
     return StaticBitmapImage::create(premulSkImageToUnPremul(skiaImage.get()));
 }
 
 ImageBitmap::ImageBitmap(HTMLImageElement* image, Optional<IntRect> cropRect, Document* document, const ImageBitmapOptions& options)
@@ skipping 28 matching lines @@
 
     // TODO(xidachen); implement the resize option.
     ParsedOptions parsedOptions = parseOptions(options, cropRect, video->bitmapSourceSize());
 
     IntRect videoRect = IntRect(IntPoint(), playerSize);
     IntRect srcRect = intersection(parsedOptions.cropRect, videoRect);
     std::unique_ptr<ImageBuffer> buffer = ImageBuffer::create(parsedOptions.cropRect.size(), NonOpaque, DoNotInitializeImagePixels);
     if (!buffer)
         return;
 
+    if (parsedOptions.flipY) {
+        buffer->canvas()->translate(0, buffer->size().height());
+        buffer->canvas()->scale(1, -1);
+    }
     IntPoint dstPoint = IntPoint(std::max(0, -parsedOptions.cropRect.x()), std::max(0, -parsedOptions.cropRect.y()));
     video->paintCurrentFrame(buffer->canvas(), IntRect(dstPoint, srcRect.size()), nullptr);
 
-    if (parsedOptions.flipY || !parsedOptions.premultiplyAlpha) {
-        RefPtr<SkImage> skiaImage = buffer->newSkImageSnapshot(PreferNoAcceleration, SnapshotReasonUnknown);
-        if (parsedOptions.flipY)
-            skiaImage = flipSkImageVertically(skiaImage.get(), PremultiplyAlpha);
-        if (!parsedOptions.premultiplyAlpha)
-            skiaImage = premulSkImageToUnPremul(skiaImage.get());
-        m_image = StaticBitmapImage::create(skiaImage.release());
-    } else {
-        m_image = StaticBitmapImage::create(buffer->newSkImageSnapshot(PreferNoAcceleration, SnapshotReasonUnknown));
-    }
+    RefPtr<SkImage> skiaImage = buffer->newSkImageSnapshot(PreferNoAcceleration, SnapshotReasonUnknown);
+    if (!parsedOptions.premultiplyAlpha)
+        skiaImage = premulSkImageToUnPremul(skiaImage.get());
+    m_image = StaticBitmapImage::create(skiaImage.release());
     m_image->setOriginClean(!video->wouldTaintOrigin(document->getSecurityOrigin()));
     m_image->setPremultiplied(parsedOptions.premultiplyAlpha);
 }
 
 ImageBitmap::ImageBitmap(HTMLCanvasElement* canvas, Optional<IntRect> cropRect, const ImageBitmapOptions& options)
 {
     ASSERT(canvas->isPaintable());
     RefPtr<Image> input = canvas->copiedImage(BackBuffer, PreferAcceleration);
     ParsedOptions parsedOptions = parseOptions(options, cropRect, canvas->bitmapSourceSize());
 
@@ skipping 265 matching lines @@
 FloatSize ImageBitmap::elementSize(const FloatSize&) const
 {
     return FloatSize(width(), height());
 }
 
 DEFINE_TRACE(ImageBitmap)
 {
 }
 
 } // namespace blink