title: Paint issue after updating Flutter
body: <p>Today when I updated Flutter I began to get an error with my paint method which had never caused any problems before:</p>
  <pre><code>@override
  void paint(
      PaintingContext context,
      Offset center, {
      Animation&lt;double&gt; activationAnimation,
      Animation&lt;double&gt; enableAnimation,
      bool isDiscrete,
      TextPainter labelPainter,
      RenderBox parentBox,
      SliderThemeData sliderTheme,
      TextDirection textDirection,
      double value,
    }) {
  </code></pre>
  <p>This is the error:</p>
  <pre><code>error: 'CustomSlider.paint' ('void Function(PaintingContext, Offset, {Animation&lt;double&gt; activationAnimation, Animation&lt;double&gt; enableAnimation, bool isDiscrete, TextPainter labelPainter, RenderBox parentBox, SliderThemeData sliderTheme, TextDirection textDirection, double value})')
  isn't a valid override of 'SliderComponentShape.paint' ('void Function(PaintingContext, Offset, {Animation&lt;double&gt; activationAnimation, Animation&lt;double&gt; enableAnimation, bool isDiscrete, TextPainter labelPainter, RenderBox parentBox, Size sizeWithOverflow, SliderThemeData sliderTheme, TextDirection textDirection, double textScaleFactor, double value})'). 
  (invalid_override at [app_name] lib/Home/path_to_file:20)
  </code></pre>