Revert of Implement overlay scrollbar fade out for non-composited scrollers.

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

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
index 179a79dff9e1fee9ca19be77ca42ea322d50f70e..7aefff29abf49721b30570ab40baa1e7a725eb7c 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
@@ -294,8 +294,6 @@
   ScrollBehavior scrollBehaviorStyle() const override;
   CompositorAnimationTimeline* compositorAnimationTimeline() const override;
 
-  void visibleSizeChanged();
-
   // FIXME: We shouldn't allow access to m_overflowRect outside this class.
   LayoutRect overflowRect() const { return m_overflowRect; }
 
@@ -321,6 +319,8 @@
   // layout has finished) but while document layout is still happening.
   void updateAfterLayout();
   void clampScrollOffsetsAfterLayout();
+
+  void didChangeScrollbarsHidden() override;
 
   void updateAfterStyleChange(const ComputedStyle*);
   void updateAfterOverflowRecalc();