Factor painting code from RenderLayerScrollableArea into ScrollableAreaPainter

Source/core/paint/LayerPainter.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/LayerPainter.h"
 
 #include "core/frame/Settings.h"
 #include "core/page/Page.h"
 #include "core/paint/FilterPainter.h"
 #include "core/paint/LayerClipRecorder.h"
+#include "core/paint/ScrollableAreaPainter.h"
 #include "core/paint/TransparencyRecorder.h"
 #include "core/rendering/ClipPathOperation.h"
 #include "core/rendering/FilterEffectRenderer.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBlock.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/svg/RenderSVGResourceClipper.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/graphics/paint/DisplayItemList.h"
@@ skipping 448 matching lines @@
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
 
         OwnPtr<LayerClipRecorder> clipRecorder;
 
         if (needsToClip(localPaintingInfo, fragment.backgroundRect)) {
             clipRecorder = adoptPtr(new LayerClipRecorder(m_renderLayer.renderer(), context, DisplayItem::ClipLayerOverflowControls, fragment.backgroundRect, &localPaintingInfo, fragment.paginationOffset, paintFlags));
         }
         if (RenderLayerScrollableArea* scrollableArea = m_renderLayer.scrollableArea())
-            scrollableArea->paintOverflowControls(context, roundedIntPoint(toPoint(fragment.layerBounds.location() - m_renderLayer.renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, m_renderLayer.compositingState()))), pixelSnappedIntRect(fragment.backgroundRect.rect()), true);
+            ScrollableAreaPainter(*scrollableArea).paintOverflowControls(context, roundedIntPoint(toPoint(fragment.layerBounds.location() - m_renderLayer.renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, m_renderLayer.compositingState()))), pixelSnappedIntRect(fragment.backgroundRect.rect()), true);
     }
 }
 
 static bool checkContainingBlockChainForPagination(RenderLayerModelObject* renderer, RenderBox* ancestorColumnsRenderer)
 {
     RenderView* view = renderer->view();
     RenderLayerModelObject* prevBlock = renderer;
     RenderBlock* containingBlock;
     for (containingBlock = renderer->containingBlock();
         containingBlock && containingBlock != view && containingBlock != ancestorColumnsRenderer;
@@ skipping 248 matching lines @@
     if (!m_renderLayer.containsDirtyOverlayScrollbars())
         return;
 
     LayerPaintingInfo paintingInfo(&m_renderLayer, enclosingIntRect(damageRect), paintBehavior, LayoutSize(), paintingRoot);
     paintLayer(context, paintingInfo, PaintLayerPaintingOverlayScrollbars);
 
     m_renderLayer.setContainsDirtyOverlayScrollbars(false);
 }
 
 } // namespace blink