Fix unscrollable scrollers after closing a <dialog>.

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@gmail.com>
@@ skipping 1584 matching lines @@
 void PaintLayerScrollableArea::updateScrollableAreaSet(bool hasOverflow) {
   LocalFrame* frame = box().frame();
   if (!frame)
     return;
 
   FrameView* frameView = frame->view();
   if (!frameView)
     return;
 
   // FIXME: Does this need to be fixed later for OOPI?
-  bool isVisibleToHitTest = box().visibleToHitTesting();
-  if (HTMLFrameOwnerElement* owner = frame->deprecatedLocalOwner())
-    isVisibleToHitTest &=
-        owner->layoutObject() && owner->layoutObject()->visibleToHitTesting();
+  bool isVisibleToHitTest = box().style()->visibleToHitTesting();
+  if (HTMLFrameOwnerElement* owner = frame->deprecatedLocalOwner()) {
+    isVisibleToHitTest &= owner->layoutObject() &&
+                          owner->layoutObject()->style()->visibleToHitTesting();
+  }
 
   bool didScrollOverflow = m_scrollsOverflow;
 
   m_scrollsOverflow = hasOverflow && isVisibleToHitTest;
   if (didScrollOverflow == scrollsOverflow())
     return;
 
   if (m_scrollsOverflow) {
     ASSERT(canHaveOverflowScrollbars(box()));
     frameView->addScrollableArea(this);
@@ skipping 345 matching lines @@
 
 void PaintLayerScrollableArea::DelayScrollOffsetClampScope::
     clampScrollableAreas() {
   for (auto& scrollableArea : *s_needsClamp)
     scrollableArea->clampScrollOffsetsAfterLayout();
   delete s_needsClamp;
   s_needsClamp = nullptr;
 }
 
 }  // namespace blink