Add a setting to do frame scrolls through the root layer.

Source/core/paint/ViewPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/paint/ViewPainter.h"
 
 #include "core/frame/FrameView.h"
+#include "core/paint/BlockPainter.h"
 #include "core/rendering/GraphicsContextAnnotator.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBox.h"
 #include "core/rendering/RenderView.h"
 
 namespace blink {
 
 void ViewPainter::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     // If we ever require layout but receive a paint anyway, something has gone horribly wrong.
     ASSERT(!m_renderView.needsLayout());
     // RenderViews should never be called to paint with an offset not on device pixels.
     ASSERT(LayoutPoint(IntPoint(paintOffset.x(), paintOffset.y())) == paintOffset);
 
     ANNOTATE_GRAPHICS_CONTEXT(paintInfo, &m_renderView);
 
     // This avoids painting garbage between columns if there is a column gap.
     if (m_renderView.frameView() && m_renderView.style()->isOverflowPaged())
         paintInfo.context->fillRect(paintInfo.rect, m_renderView.frameView()->baseBackgroundColor());
 
     m_renderView.paintObject(paintInfo, paintOffset);
+    BlockPainter(m_renderView).paintOverflowControlsIfNeeded(paintInfo, paintOffset);
 }
 
 static inline bool rendererObscuresBackground(RenderBox* rootBox)
 {
     ASSERT(rootBox);
     RenderStyle* style = rootBox->style();
     if (style->visibility() != VISIBLE
         || style->opacity() != 1
         || style->hasFilter()
         || style->hasTransform())
@@ skipping 47 matching lines @@
 {
     ASSERT(rootBox);
     // CSS Boxes always fill the viewport background (see paintRootBoxFillLayers)
     if (!rootBox->isSVG())
         return true;
 
     return rootBox->frameRect().contains(m_renderView.frameRect());
 }
 
 } // namespace blink