Implement InterpolationMedium to filter animated images

Source/core/rendering/RenderBoxModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google 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
@@ skipping 82 matching lines @@
         return;
 
     layer()->contentChanged(changeType);
 }
 
 bool RenderBoxModelObject::hasAcceleratedCompositing() const
 {
     return view()->compositor()->hasAcceleratedCompositing();
 }
 
-bool RenderBoxModelObject::shouldPaintAtLowQuality(GraphicsContext* context, Image* image, const void* layer, const LayoutSize& size)
+InterpolationQuality RenderBoxModelObject::chooseInterpolationQuality(GraphicsContext* context, Image* image, const void* layer, const LayoutSize& size)
 {
-    return ImageQualityController::imageQualityController()->shouldPaintAtLowQuality(context, this, image, layer, size);
+    return ImageQualityController::imageQualityController()->chooseInterpolationQuality(context, this, image, layer, size);
 }
 
 RenderBoxModelObject::RenderBoxModelObject(ContainerNode* node)
     : RenderLayerModelObject(node)
 {
 }
 
 RenderBoxModelObject::~RenderBoxModelObject()
 {
     ImageQualityController::remove(this);
@@ skipping 579 matching lines @@
 
     // no progressive loading of the background image
     if (shouldPaintBackgroundImage) {
         BackgroundImageGeometry geometry;
         calculateBackgroundImageGeometry(bgLayer, scrolledPaintRect, geometry, backgroundObject);
         geometry.clip(paintInfo.rect);
         if (!geometry.destRect().isEmpty()) {
             CompositeOperator compositeOp = op == CompositeSourceOver ? bgLayer->composite() : op;
             RenderObject* clientForBackgroundImage = backgroundObject ? backgroundObject : this;
             RefPtr<Image> image = bgImage->image(clientForBackgroundImage, geometry.tileSize());
-            bool useLowQualityScaling = shouldPaintAtLowQuality(context, image.get(), bgLayer, geometry.tileSize());
+            InterpolationQuality interpolationQuality = chooseInterpolationQuality(context, image.get(), bgLayer, geometry.tileSize());
             if (bgLayer->maskSourceType() == MaskLuminance)
                 context->setColorFilter(ColorFilterLuminanceToAlpha);
+            InterpolationQuality previousInterpolationQuality = context->imageInterpolationQuality();
+            context->setImageInterpolationQuality(interpolationQuality);
             context->drawTiledImage(image.get(), geometry.destRect(), geometry.relativePhase(), geometry.tileSize(),
-                compositeOp, useLowQualityScaling, bgLayer->blendMode(), geometry.spaceSize());
+                compositeOp, bgLayer->blendMode(), geometry.spaceSize());
+            context->setImageInterpolationQuality(previousInterpolationQuality);
         }
     }
 
     if (bgLayer->clip() == TextFillBox) {
         // Create the text mask layer.
         context->setCompositeOperation(CompositeDestinationIn);
         context->beginTransparencyLayer(1);
 
         // FIXME: Workaround for https://code.google.com/p/skia/issues/detail?id=1291.
         context->clearRect(maskRect);
@@ skipping 2086 matching lines @@
     ASSERT(!beforeChild || toBoxModelObject == beforeChild->parent());
     for (RenderObject* child = startChild; child && child != endChild; ) {
         // Save our next sibling as moveChildTo will clear it.
         RenderObject* nextSibling = child->nextSibling();
         moveChildTo(toBoxModelObject, child, beforeChild, fullRemoveInsert);
         child = nextSibling;
     }
 }
 
 } // namespace WebCore