Implement image-rendering:pixelated for directly composited images.

Source/platform/graphics/GraphicsLayer.cpp

Index: Source/platform/graphics/GraphicsLayer.cpp
diff --git a/Source/platform/graphics/GraphicsLayer.cpp b/Source/platform/graphics/GraphicsLayer.cpp
index d3361c17ecccf25635b285de69b916f51119d2de..c4c88d81ea129a52b5fa0a24e4a8c73ee950ea2c 100644
--- a/Source/platform/graphics/GraphicsLayer.cpp
+++ b/Source/platform/graphics/GraphicsLayer.cpp
@@ -1005,6 +1005,12 @@ void GraphicsLayer::setFilters(const FilterOperations& filters)
     m_layer->layer()->setFilters(*webFilters);
 }
 
+void GraphicsLayer::setFilterLevel(SkPaint::FilterLevel filterLevel)
+{
+    if (m_imageLayer)
+        m_imageLayer->setNearestNeighbor(filterLevel == SkPaint::kNone_FilterLevel);
+}
+
 void GraphicsLayer::setPaintingPhase(GraphicsLayerPaintingPhase phase)
 {
     if (m_paintingPhase == phase)