Move paint code for RenderScrollbar and RenderScrollbarPart into ScrollbarPainter.

Source/core/rendering/RenderLayerScrollableArea.cpp

Index: Source/core/rendering/RenderLayerScrollableArea.cpp
diff --git a/Source/core/rendering/RenderLayerScrollableArea.cpp b/Source/core/rendering/RenderLayerScrollableArea.cpp
index 308e7016e74a1e8f5cd0b1f9acb5855104f009e1..d5ba03a633bf3881c315a8f3d19516e7f4c4015f 100644
--- a/Source/core/rendering/RenderLayerScrollableArea.cpp
+++ b/Source/core/rendering/RenderLayerScrollableArea.cpp
@@ -58,6 +58,7 @@
 #include "core/page/FocusController.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
+#include "core/paint/ScrollbarPainter.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderScrollbar.h"
 #include "core/rendering/RenderScrollbarPart.h"
@@ -1070,7 +1071,7 @@ void RenderLayerScrollableArea::paintScrollCorner(GraphicsContext* context, cons
         return;
 
     if (m_scrollCorner) {
-        m_scrollCorner->paintIntoRect(context, paintOffset, absRect);
+        ScrollbarPainter::paintIntoRect(m_scrollCorner, context, paintOffset, absRect);
         return;
     }
 
@@ -1178,7 +1179,7 @@ void RenderLayerScrollableArea::paintResizer(GraphicsContext* context, const Int
         return;
 
     if (m_resizer) {
-        m_resizer->paintIntoRect(context, paintOffset, absRect);
+        ScrollbarPainter::paintIntoRect(m_resizer, context, paintOffset, absRect);
         return;
     }