Revert of antialias matrix-image-filter to get smooth diagonals (patchset #6 id:80002 of https://codereview.chromium.org/1134743003/)

Reason for revert:
likely affect layouttests, so need to add a guard

Original issue's description:
> antialias matrix-image-filter to get smooth diagonals
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/fa33f5a6b770130acdc55f2ffe19dd545665726a

TBR=senorblanco@google.com,robertphillips@google.com,bsalomon@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1128823010

1 files changed, 4 insertions, 4 deletions

diff --git a/src/core/SkMatrixImageFilter.cpp b/src/core/SkMatrixImageFilter.cpp
index 1e76362285..a61867e041 100644
--- a/src/core/SkMatrixImageFilter.cpp
+++ b/src/core/SkMatrixImageFilter.cpp
@@ -76,13 +76,13 @@ bool SkMatrixImageFilter::onFilterImage(Proxy* proxy,
         return false;
     }
 
-    SkPaint paint;
-    paint.setFilterQuality(fFilterQuality);
-    paint.setAntiAlias(true);   // since we may be rotated, we definitely want a smooth edge
-    
     SkCanvas canvas(device.get());
     canvas.translate(-SkIntToScalar(dstBounds.x()), -SkIntToScalar(dstBounds.y()));
     canvas.concat(matrix);
+    SkPaint paint;
+
+    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+    paint.setFilterQuality(fFilterQuality);
     canvas.drawBitmap(src, srcRect.x(), srcRect.y(), &paint);
 
     *result = device.get()->accessBitmap(false);