Expand PaintLayer clip to account for hidden URL bar with document.rootScroller

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 3678 matching lines @@
 
   // We need to perform this const_cast since maximumScrollOffsetInt is a const
   // method but we can't make layoutViewportScrollableArea const since it can
   // return |this|. Once root-layer-scrolls ships layoutViewportScrollableArea
   // can be made const.
   const ScrollableArea* layoutViewport =
       const_cast<FrameView*>(this)->layoutViewportScrollableArea();
   TopDocumentRootScrollerController& controller =
       host->globalRootScrollerController();
   if (layoutViewport == controller.rootScrollerArea())
-    visibleSize = controller.rootScrollerVisibleArea();
+    visibleSize = controller.visibleContentRect(ExcludeScrollbars).size();
 
   IntSize maximumOffset =
       toIntSize(-scrollOrigin() + (contentBounds - visibleSize));
   return maximumOffset.expandedTo(minimumScrollOffsetInt());
 }
 
 void FrameView::addChild(Widget* child) {
   ASSERT(child != this && !child->parent());
   child->setParent(this);
   m_children.add(child);
@@ skipping 1288 matching lines @@
   // This is the top-level frame, so no mapping necessary.
   if (m_frame->isMainFrame())
     return;
 
   LayoutRect viewportIntersectionRect(remoteViewportIntersection());
   transformState.move(
       LayoutSize(-viewportIntersectionRect.x(), -viewportIntersectionRect.y()));
 }
 
 }  // namespace blink