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

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 a3d01d7eb6fcea53063de47449bf44d5c0a2c3e1..30c217d4ed09101fd51363470204871914f1f04d 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -170,7 +170,7 @@
   if (m_resizer)
     m_resizer->destroy();
 
-  clearScrollableArea();
+  clearScrollAnimators();
 
   // Note: it is not safe to call ScrollAnchor::clear if the document is being
   // destroyed, because LayoutObjectChildList::removeChildNode skips the call to
@@ -366,7 +366,6 @@
   if (scrollOffset() == newOffset)
     return;
 
-  showOverlayScrollbars();
   ScrollOffset scrollDelta = scrollOffset() - newOffset;
   m_scrollOffset = newOffset;
 
@@ -516,10 +515,6 @@
               max(0, layer()->size().height() - horizontalScrollbarHeight)));
 }
 
-void PaintLayerScrollableArea::visibleSizeChanged() {
-  showOverlayScrollbars();
-}
-
 int PaintLayerScrollableArea::visibleHeight() const {
   return layer()->size().height();
 }
@@ -551,7 +546,6 @@
 }
 
 void PaintLayerScrollableArea::scrollbarVisibilityChanged() {
-  updateScrollbarsEnabledState();
   if (LayoutView* view = box().view())
     return view->clearHitTestCache();
 }
@@ -648,8 +642,6 @@
 }
 
 void PaintLayerScrollableArea::updateScrollDimensions() {
-  if (m_overflowRect.size() != box().layoutOverflowRect().size())
-    contentsResized();
   m_overflowRect = box().layoutOverflowRect();
   box().flipForWritingMode(m_overflowRect);
   updateScrollOrigin();
@@ -660,6 +652,10 @@
     ScrollType scrollType) {
   cancelScrollAnimation();
   scrollOffsetChanged(offset, scrollType);
+}
+
+void PaintLayerScrollableArea::didChangeScrollbarsHidden() {
+  updateScrollbarsEnabledState();
 }
 
 void PaintLayerScrollableArea::updateScrollbarsEnabledState() {