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 b7ee540572d957eeae60dbabca60a60d1e83f251..8abad8fe52d6c852b72a69322411356155d37cea 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
@@ -295,8 +295,6 @@
   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; }
 
@@ -322,6 +320,8 @@
   // layout has finished) but while document layout is still happening.
   void updateAfterLayout();
   void clampScrollOffsetsAfterLayout();
+
+  void didChangeScrollbarsHidden() override;
 
   void updateAfterStyleChange(const ComputedStyle*);
   void updateAfterOverflowRecalc();