Method drawTo

test/background_fill_optimizer_test.cpp:862–868

 private:
  void drawTo(const Surface& s) const override {
    DisplayOutput& out = s.out();
    out.setAddress(window_.xMin(), window_.yMin(), window_.xMax(),
                   window_.yMax(), BlendingMode::kSource);
    out.fill(first_, first_count_);
    out.fill(second_, second_count_);
  }

  Box window_;
  Color first_;