Set scrollbar enabled state for overflow:auto.

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 9ced75cbdf05708c2e71e5bdb9db1eb12d60eab1..39afec388f4d7474c38c75129680c3a7ad0b2719 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -659,17 +659,14 @@ void PaintLayerScrollableArea::updateScrollDimensions() {
 }
 
 void PaintLayerScrollableArea::updateScrollbarEnabledState() {
-  bool forceDisabled =
+  bool forceDisable =
       ScrollbarTheme::theme().shouldDisableInvisibleScrollbars() &&
       scrollbarsHidden();
-  // overflow:scroll should just enable/disable.
-  if (box().style()->overflowX() == OverflowScroll && horizontalScrollbar()) {
-    horizontalScrollbar()->setEnabled(hasHorizontalOverflow() &&
-                                      !forceDisabled);
-  }
-  if (box().style()->overflowY() == OverflowScroll && verticalScrollbar()) {
-    verticalScrollbar()->setEnabled(hasVerticalOverflow() && !forceDisabled);
-  }
+
+  if (horizontalScrollbar())
+    horizontalScrollbar()->setEnabled(hasHorizontalOverflow() && !forceDisable);
+  if (verticalScrollbar())
+    verticalScrollbar()->setEnabled(hasVerticalOverflow() && !forceDisable);
 }
 
 void PaintLayerScrollableArea::setScrollOffsetUnconditionally(