Fix CSS clips cannot be correctly handled by composited scroller

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
index 7d0a445d4c49cfe9bc86cec82fa8d93f46933928..2df3456bcfaa6ba6bc5be701bc07a9111c9d11b2 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -1754,7 +1754,8 @@ static bool layerNeedsCompositedScrolling(
   // with the results.
   return !(layer->size().isEmpty() || layer->hasDescendantWithClipPath() ||
            layer->hasAncestorWithClipPath() ||
-           layer->layoutObject()->style()->hasBorderRadius());
+           layer->layoutObject()->style()->hasBorderRadius() ||
+           !layer->layoutObject()->style()->hasAutoClip());

[chrishtr, 2016/12/28 16:17:44]

Instead, write this:

layer->layoutObject()->hasClip()

[yigu, 2016/12/28 18:42:06]

Done.

 }
 
 void PaintLayerScrollableArea::updateNeedsCompositedScrolling(