Unnecessary new (#20138)

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests
diff --git a/dev/manual_tests/lib/material_arc.dart b/dev/manual_tests/lib/material_arc.dart
index d8aa502..e4afb81 100644
--- a/dev/manual_tests/lib/material_arc.dart
+++ b/dev/manual_tests/lib/material_arc.dart
@@ -55,7 +55,7 @@
   final Animation<double> _repaint;
 
   void drawPoint(Canvas canvas, Offset point, Color color) {
-    final Paint paint = new Paint()
+    final Paint paint = Paint()
       ..color = color.withOpacity(0.25)
       ..style = PaintingStyle.fill;
     canvas.drawCircle(point, _kPointRadius, paint);
@@ -68,7 +68,7 @@
 
   @override
   void paint(Canvas canvas, Size size) {
-    final Paint paint = new Paint();
+    final Paint paint = Paint();
 
     if (arc.center != null)
       drawPoint(canvas, arc.center, Colors.grey.shade400);
@@ -108,11 +108,11 @@
   final AnimationController controller;
 
   @override
-  _PointDemoState createState() => new _PointDemoState();
+  _PointDemoState createState() => _PointDemoState();
 }
 
 class _PointDemoState extends State<_PointDemo> {
-  final GlobalKey _painterKey = new GlobalKey();
+  final GlobalKey _painterKey = GlobalKey();
 
   CurvedAnimation _animation;
   _DragTarget _dragTarget;
@@ -123,7 +123,7 @@
   @override
   void initState() {
     super.initState();
-    _animation = new CurvedAnimation(parent: widget.controller, curve: Curves.fastOutSlowIn);
+    _animation = CurvedAnimation(parent: widget.controller, curve: Curves.fastOutSlowIn);
   }
 
   @override
@@ -135,7 +135,7 @@
   Drag _handleOnStart(Offset position) {
     // TODO(hansmuller): allow the user to drag both points at the same time.
     if (_dragTarget != null)
-      return new _IgnoreDrag();
+      return _IgnoreDrag();
 
     final RenderBox box = _painterKey.currentContext.findRenderObject();
     final double startOffset = (box.localToGlobal(_begin) - position).distanceSquared;
@@ -149,7 +149,7 @@
         _dragTarget = null;
     });
 
-    return new _DragHandler(_handleDragUpdate, _handleDragCancel, _handleDragEnd);
+    return _DragHandler(_handleDragUpdate, _handleDragCancel, _handleDragEnd);
   }
 
   void _handleDragUpdate(DragUpdateDetails details) {
@@ -181,36 +181,36 @@
     final Size screenSize = MediaQuery.of(context).size;
     if (_screenSize == null || _screenSize != screenSize) {
       _screenSize = screenSize;
-      _begin = new Offset(screenSize.width * 0.5, screenSize.height * 0.2);
-      _end = new Offset(screenSize.width * 0.1, screenSize.height * 0.4);
+      _begin = Offset(screenSize.width * 0.5, screenSize.height * 0.2);
+      _end = Offset(screenSize.width * 0.1, screenSize.height * 0.4);
     }
 
-    final MaterialPointArcTween arc = new MaterialPointArcTween(begin: _begin, end: _end);
-    return new RawGestureDetector(
+    final MaterialPointArcTween arc = MaterialPointArcTween(begin: _begin, end: _end);
+    return RawGestureDetector(
       behavior: _dragTarget == null ? HitTestBehavior.deferToChild : HitTestBehavior.opaque,
       gestures: <Type, GestureRecognizerFactory>{
-        ImmediateMultiDragGestureRecognizer: new GestureRecognizerFactoryWithHandlers<ImmediateMultiDragGestureRecognizer>(
-          () => new ImmediateMultiDragGestureRecognizer(),
+        ImmediateMultiDragGestureRecognizer: GestureRecognizerFactoryWithHandlers<ImmediateMultiDragGestureRecognizer>(
+          () => ImmediateMultiDragGestureRecognizer(),
           (ImmediateMultiDragGestureRecognizer instance) {
             instance
               ..onStart = _handleOnStart;
           },
         ),
       },
-      child: new ClipRect(
-        child: new CustomPaint(
+      child: ClipRect(
+        child: CustomPaint(
           key: _painterKey,
-          foregroundPainter: new _PointDemoPainter(
+          foregroundPainter: _PointDemoPainter(
             repaint: _animation,
             arc: arc
           ),
           // Watch out: if this IgnorePointer is left out, then gestures that
           // fail _PointDemoPainter.hitTest() will still be recognized because
           // they do overlap this child, which is as big as the CustomPaint.
-          child: new IgnorePointer(
-            child: new Padding(
+          child: IgnorePointer(
+            child: Padding(
               padding: const EdgeInsets.all(16.0),
-              child: new Text(
+              child: Text(
                 'Tap the refresh button to run the animation. Drag the green '
                 "and red points to change the animation's path.",
                 style: Theme.of(context).textTheme.caption.copyWith(fontSize: 16.0)
@@ -233,7 +233,7 @@
   final Animation<double> _repaint;
 
   void drawPoint(Canvas canvas, Offset p, Color color) {
-    final Paint paint = new Paint()
+    final Paint paint = Paint()
       ..color = color.withOpacity(0.25)
       ..style = PaintingStyle.fill;
     canvas.drawCircle(p, _kPointRadius, paint);
@@ -245,7 +245,7 @@
   }
 
   void drawRect(Canvas canvas, Rect rect, Color color) {
-    final Paint paint = new Paint()
+    final Paint paint = Paint()
       ..color = color.withOpacity(0.25)
       ..strokeWidth = 4.0
       ..style = PaintingStyle.stroke;
@@ -276,11 +276,11 @@
   final AnimationController controller;
 
   @override
-  _RectangleDemoState createState() => new _RectangleDemoState();
+  _RectangleDemoState createState() => _RectangleDemoState();
 }
 
 class _RectangleDemoState extends State<_RectangleDemo> {
-  final GlobalKey _painterKey = new GlobalKey();
+  final GlobalKey _painterKey = GlobalKey();
 
   CurvedAnimation _animation;
   _DragTarget _dragTarget;
@@ -291,7 +291,7 @@
   @override
   void initState() {
     super.initState();
-    _animation = new CurvedAnimation(parent: widget.controller, curve: Curves.fastOutSlowIn);
+    _animation = CurvedAnimation(parent: widget.controller, curve: Curves.fastOutSlowIn);
   }
 
   @override
@@ -303,7 +303,7 @@
   Drag _handleOnStart(Offset position) {
     // TODO(hansmuller): allow the user to drag both points at the same time.
     if (_dragTarget != null)
-      return new _IgnoreDrag();
+      return _IgnoreDrag();
 
     final RenderBox box = _painterKey.currentContext.findRenderObject();
     final double startOffset = (box.localToGlobal(_begin.center) - position).distanceSquared;
@@ -316,7 +316,7 @@
       else
         _dragTarget = null;
     });
-    return new _DragHandler(_handleDragUpdate, _handleDragCancel, _handleDragEnd);
+    return _DragHandler(_handleDragUpdate, _handleDragCancel, _handleDragEnd);
   }
 
   void _handleDragUpdate(DragUpdateDetails details) {
@@ -348,42 +348,42 @@
     final Size screenSize = MediaQuery.of(context).size;
     if (_screenSize == null || _screenSize != screenSize) {
       _screenSize = screenSize;
-      _begin = new Rect.fromLTWH(
+      _begin = Rect.fromLTWH(
         screenSize.width * 0.5, screenSize.height * 0.2,
         screenSize.width * 0.4, screenSize.height * 0.2
       );
-      _end = new Rect.fromLTWH(
+      _end = Rect.fromLTWH(
         screenSize.width * 0.1, screenSize.height * 0.4,
         screenSize.width * 0.3, screenSize.height * 0.3
       );
     }
 
-    final MaterialRectArcTween arc = new MaterialRectArcTween(begin: _begin, end: _end);
-    return new RawGestureDetector(
+    final MaterialRectArcTween arc = MaterialRectArcTween(begin: _begin, end: _end);
+    return RawGestureDetector(
       behavior: _dragTarget == null ? HitTestBehavior.deferToChild : HitTestBehavior.opaque,
       gestures: <Type, GestureRecognizerFactory>{
-        ImmediateMultiDragGestureRecognizer: new GestureRecognizerFactoryWithHandlers<ImmediateMultiDragGestureRecognizer>(
-          () => new ImmediateMultiDragGestureRecognizer(),
+        ImmediateMultiDragGestureRecognizer: GestureRecognizerFactoryWithHandlers<ImmediateMultiDragGestureRecognizer>(
+          () => ImmediateMultiDragGestureRecognizer(),
           (ImmediateMultiDragGestureRecognizer instance) {
             instance
               ..onStart = _handleOnStart;
           },
         ),
       },
-      child: new ClipRect(
-        child: new CustomPaint(
+      child: ClipRect(
+        child: CustomPaint(
           key: _painterKey,
-          foregroundPainter: new _RectangleDemoPainter(
+          foregroundPainter: _RectangleDemoPainter(
             repaint: _animation,
             arc: arc
           ),
           // Watch out: if this IgnorePointer is left out, then gestures that
           // fail _RectDemoPainter.hitTest() will still be recognized because
           // they do overlap this child, which is as big as the CustomPaint.
-          child: new IgnorePointer(
-            child: new Padding(
+          child: IgnorePointer(
+            child: Padding(
               padding: const EdgeInsets.all(16.0),
-              child: new Text(
+              child: Text(
                 'Tap the refresh button to run the animation. Drag the rectangles '
                 "to change the animation's path.",
                 style: Theme.of(context).textTheme.caption.copyWith(fontSize: 16.0)
@@ -400,8 +400,8 @@
 
 class _ArcDemo {
   _ArcDemo(this.title, this.builder, TickerProvider vsync)
-    : controller = new AnimationController(duration: const Duration(milliseconds: 500), vsync: vsync),
-      key = new GlobalKey(debugLabel: title);
+    : controller = AnimationController(duration: const Duration(milliseconds: 500), vsync: vsync),
+      key = GlobalKey(debugLabel: title);
 
   final String title;
   final _DemoBuilder builder;
@@ -413,7 +413,7 @@
   const AnimationDemo({ Key key }) : super(key: key);
 
   @override
-  _AnimationDemoState createState() => new _AnimationDemoState();
+  _AnimationDemoState createState() => _AnimationDemoState();
 }
 
 class _AnimationDemoState extends State<AnimationDemo> with TickerProviderStateMixin {
@@ -423,14 +423,14 @@
   void initState() {
     super.initState();
     _allDemos = <_ArcDemo>[
-      new _ArcDemo('POINT', (_ArcDemo demo) {
-        return new _PointDemo(
+      _ArcDemo('POINT', (_ArcDemo demo) {
+        return _PointDemo(
           key: demo.key,
           controller: demo.controller
         );
       }, this),
-      new _ArcDemo('RECTANGLE', (_ArcDemo demo) {
-        return new _RectangleDemo(
+      _ArcDemo('RECTANGLE', (_ArcDemo demo) {
+        return _RectangleDemo(
           key: demo.key,
           controller: demo.controller
         );
@@ -446,18 +446,18 @@
 
   @override
   Widget build(BuildContext context) {
-    return new DefaultTabController(
+    return DefaultTabController(
       length: _allDemos.length,
-      child: new Scaffold(
-        appBar: new AppBar(
+      child: Scaffold(
+        appBar: AppBar(
           title: const Text('Animation'),
-          bottom: new TabBar(
-            tabs: _allDemos.map((_ArcDemo demo) => new Tab(text: demo.title)).toList(),
+          bottom: TabBar(
+            tabs: _allDemos.map((_ArcDemo demo) => Tab(text: demo.title)).toList(),
           ),
         ),
-        floatingActionButton: new Builder(
+        floatingActionButton: Builder(
           builder: (BuildContext context) {
-            return new FloatingActionButton(
+            return FloatingActionButton(
               child: const Icon(Icons.refresh),
               onPressed: () {
                 _play(_allDemos[DefaultTabController.of(context).index]);
@@ -465,7 +465,7 @@
             );
           },
         ),
-        body: new TabBarView(
+        body: TabBarView(
           children: _allDemos.map((_ArcDemo demo) => demo.builder(demo)).toList()
         )
       )
@@ -474,7 +474,7 @@
 }
 
 void main() {
-  runApp(new MaterialApp(
+  runApp(MaterialApp(
     home: const AnimationDemo(),
   ));
 }