Currently, GraphicsLayer deals with repaint count. It is weird because each tile can have different repaint count. So each tile (for TextureMapperTiledBackingStore and CoordinatedBackingStore) should deal with repaint count.
I think that a tile owns repaint count is correct behavior. (e.g. implement repaintCount to TextureMapperTile) But, For this behavior, we should change "paintCount" in InspectorType to proper name and proper class(name like Tile, not Layer). Also mac code use "GraphicsLayer->repaintCount" way here and there. So, I think we need mac and inspector people help.