Make LayoutBoxModelObject const when passed to calculateBackgroundImageGeometry

Source/core/paint/BoxPainter.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/BoxPainter.h"
 
 #include "core/HTMLNames.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
@@ skipping 566 matching lines @@
     int space = -1;
 
     if (numberOfTiles > 1) {
         // Spec doesn't specify rounding, so use the same method as for background-repeat: round.
         space = lroundf((areaSize - numberOfTiles * tileSize) / (float)(numberOfTiles - 1));
     }
 
     return space;
 }
 
-void BoxPainter::calculateBackgroundImageGeometry(LayoutBoxModelObject& obj, const LayoutBoxModelObject* paintContainer, const GlobalPaintFlags globalPaintFlags, const FillLayer& fillLayer, const LayoutRect& paintRect,
+void BoxPainter::calculateBackgroundImageGeometry(const LayoutBoxModelObject& obj, const LayoutBoxModelObject* paintContainer, const GlobalPaintFlags globalPaintFlags, const FillLayer& fillLayer, const LayoutRect& paintRect,
     BackgroundImageGeometry& geometry, LayoutObject* backgroundObject)
 {
     LayoutUnit left = 0;
     LayoutUnit top = 0;
     IntSize positioningAreaSize;
     IntRect snappedPaintRect = pixelSnappedIntRect(paintRect);
     bool isLayoutView = obj.isLayoutView();
     const LayoutBox* rootBox = nullptr;
     if (isLayoutView) {
         // It is only possible reach here when root element has a box.
@@ skipping 446 matching lines @@
     }
 }
 
 bool BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(const ComputedStyle& style, const Document& document)
 {
     return document.printing() && style.printColorAdjust() == PrintColorAdjustEconomy
         && (!document.settings() || !document.settings()->shouldPrintBackgrounds());
 }
 
 } // namespace blink