Remove usesCompositedScrolling

sky/engine/core/rendering/RenderBox.cpp

Index: sky/engine/core/rendering/RenderBox.cpp
diff --git a/sky/engine/core/rendering/RenderBox.cpp b/sky/engine/core/rendering/RenderBox.cpp
index 1f2f6e35c49746fdf79ad5bcca98bd2e83435582..dfc50a046601d7b3eafbe1cfa9d5f12d42b0c214 100644
--- a/sky/engine/core/rendering/RenderBox.cpp
+++ b/sky/engine/core/rendering/RenderBox.cpp
@@ -474,11 +474,6 @@ bool RenderBox::canBeProgramaticallyScrolled() const
     return node && node->hasEditableStyle();
 }
 
-bool RenderBox::usesCompositedScrolling() const
-{
-    return hasOverflowClip() && hasLayer() && layer()->scrollableArea()->usesCompositedScrolling();
-}
-
 void RenderBox::autoscroll(const IntPoint& position)
 {
     LocalFrame* frame = this->frame();
@@ -587,10 +582,6 @@ void RenderBox::applyCachedClipAndScrollOffsetForPaintInvalidation(LayoutRect& p
 
     paintRect.move(-scrolledContentOffset()); // For overflow:auto/scroll/hidden.
 
-    // Do not clip scroll layer contents to reduce the number of paint invalidations while scrolling.
-    if (usesCompositedScrolling())
-        return;
-
     // height() is inaccurate if we're in the middle of a layout of this RenderBox, so use the
     // layer's size instead. Even if the layer's size is wrong, the layer itself will issue paint invalidations
     // anyway if its size does change.
@@ -3721,17 +3712,6 @@ LayoutRect RenderBox::noOverflowRect() const
     return rect;
 }
 
-LayoutRect RenderBox::overflowRectForPaintRejection() const
-{
-    LayoutRect overflowRect = visualOverflowRect();
-    if (!m_overflow || !usesCompositedScrolling())
-        return overflowRect;
-
-    overflowRect.unite(layoutOverflowRect());
-    overflowRect.move(-scrolledContentOffset());
-    return overflowRect;
-}
-
 LayoutUnit RenderBox::offsetLeft() const
 {
     return adjustedPositionRelativeToOffsetParent(topLeftLocation()).x();