Fix const correctness of containerForRepaint

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 516 matching lines @@
         os = os->nextInPreOrder();
     }
 
     // Now create a single bounding box rect that encloses the whole selection.
     LayoutRect selRect;
     SelectionMap::iterator end = selectedObjects.end();
     for (SelectionMap::iterator i = selectedObjects.begin(); i != end; ++i) {
         RenderSelectionInfo* info = i->value.get();
         // RenderSelectionInfo::rect() is in the coordinates of the repaintContainer, so map to page coordinates.
         LayoutRect currRect = info->rect();
-        if (RenderLayerModelObject* repaintContainer = info->repaintContainer()) {
+        if (const RenderLayerModelObject* repaintContainer = info->repaintContainer()) {
             FloatQuad absQuad = repaintContainer->localToAbsoluteQuad(FloatRect(currRect));
             currRect = absQuad.enclosingBoundingBox();
         }
         selRect.unite(currRect);
     }
     return pixelSnappedIntRect(selRect);
 }
 
 void RenderView::repaintSelection() const
 {
@@ skipping 408 matching lines @@
     return viewWidth(IncludeScrollbars) / scale;
 }
 
 double RenderView::layoutViewportHeight() const
 {
     float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 } // namespace WebCore