Implement image-rendering:pixelated for accelerated 2D canvases.

Source/platform/graphics/Canvas2DImageBufferSurface.h

Index: Source/platform/graphics/Canvas2DImageBufferSurface.h
diff --git a/Source/platform/graphics/Canvas2DImageBufferSurface.h b/Source/platform/graphics/Canvas2DImageBufferSurface.h
index fb9f71ac9b2897d81d408725d1162e80209e695b..8578976cc380b6ff71f8c48a306f944c41b93220 100644
--- a/Source/platform/graphics/Canvas2DImageBufferSurface.h
+++ b/Source/platform/graphics/Canvas2DImageBufferSurface.h
@@ -61,6 +61,7 @@ public:
     virtual WebLayer* layer() const override { return m_layerBridge->layer(); }
     virtual Platform3DObject getBackingTexture() const override { return m_layerBridge->getBackingTexture(); }
     virtual bool isAccelerated() const override { return m_layerBridge->isAccelerated(); }
+    virtual void setFilterLevel(SkPaint::FilterLevel filterLevel) override { m_layerBridge->setFilterLevel(filterLevel); };
     virtual void setIsHidden(bool hidden) override { m_layerBridge->setIsHidden(hidden); }
     virtual void setImageBuffer(ImageBuffer* imageBuffer) override { m_layerBridge->setImageBuffer(imageBuffer); }