Make body element background image use correct interpolation quality.

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 435 matching lines @@
     // no progressive loading of the background image
     if (shouldPaintBackgroundImage) {
         BackgroundImageGeometry geometry;
         calculateBackgroundImageGeometry(obj, paintInfo.paintContainer(), bgLayer, scrolledPaintRect, geometry, backgroundObject);
         if (!geometry.destRect().isEmpty()) {
             SkXfermode::Mode bgOp = WebCoreCompositeToSkiaComposite(bgLayer.composite(), bgLayer.blendMode());
             // if op != SkXfermode::kSrcOver_Mode, a mask is being painted.
             SkXfermode::Mode compositeOp = op == SkXfermode::kSrcOver_Mode ? bgOp : op;
             LayoutObject* clientForBackgroundImage = backgroundObject ? backgroundObject : &obj;
             RefPtr<Image> image = bgImage->image(clientForBackgroundImage, geometry.tileSize());
-            InterpolationQuality interpolationQuality = chooseInterpolationQuality(obj, context, image.get(), &bgLayer, LayoutSize(geometry.tileSize()));
+            InterpolationQuality interpolationQuality = chooseInterpolationQuality(*clientForBackgroundImage, context, image.get(), &bgLayer, LayoutSize(geometry.tileSize()));
             if (bgLayer.maskSourceType() == MaskLuminance)
                 context->setColorFilter(ColorFilterLuminanceToAlpha);
             InterpolationQuality previousInterpolationQuality = context->imageInterpolationQuality();
             context->setImageInterpolationQuality(interpolationQuality);
             TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "PaintImage", "data", InspectorPaintImageEvent::data(obj, *bgImage));
             context->drawTiledImage(image.get(), geometry.destRect(), geometry.phase(), geometry.tileSize(),
                 compositeOp, geometry.spaceSize());
             context->setImageInterpolationQuality(previousInterpolationQuality);
         }
     }
@@ skipping 314 matching lines @@
         geometry.setNoRepeatY(top + yOffset);
         geometry.setSpaceSize(IntSize(geometry.spaceSize().width(), 0));
     }
 
     if (fixedAttachment)
         geometry.useFixedAttachment(snappedPaintRect.location());
 
     geometry.clip(snappedPaintRect);
 }
 
-InterpolationQuality BoxPainter::chooseInterpolationQuality(LayoutBoxModelObject& obj, GraphicsContext* context, Image* image, const void* layer, const LayoutSize& size)
+InterpolationQuality BoxPainter::chooseInterpolationQuality(LayoutObject& obj, GraphicsContext* context, Image* image, const void* layer, const LayoutSize& size)
 {
     return ImageQualityController::imageQualityController()->chooseInterpolationQuality(context, &obj, image, layer, size);
 }
 
 bool BoxPainter::fixedBackgroundPaintsInLocalCoordinates(const LayoutObject& obj)
 {
     if (!obj.isDocumentElement())
         return false;
 
     if (obj.view()->frameView() && obj.view()->frameView()->paintBehavior() & PaintBehaviorFlattenCompositingLayers)
@@ skipping 1401 matching lines @@
 
     FloatPoint secondQuad[4];
     secondQuad[0] = quad[0];
     secondQuad[1] = FloatPoint(quad[0].x() - r1 * cx, quad[0].y() - r1 * cy);
     secondQuad[2] = quad[2];
     secondQuad[3] = quad[3];
     graphicsContext->clipPolygon(4, secondQuad, !secondEdgeMatches);
 }
 
 } // namespace blink