Fix warnings.

Runtime/debugger/diagnostics.cs

             }
         }
     }
+#pragma warning restore 0659
+#pragma warning restore 0661
 
     public class InspectorInstanceRef : IEquatable<InspectorInstanceRef> {
         public readonly string id;

Runtime/flow/physical_shape_layer.cs

         Path _path;
 #pragma warning disable 0414
         bool _isRect;
+#pragma warning restore 0414
         Rect _frameRRect;
         Clip _clip_behavior;
 

Runtime/foundation/key.cs

             return !Equals(left, right);
         }
     }
+#pragma warning restore 0660
+#pragma warning restore 0661
 
     public abstract class LocalKey : Key {
         protected LocalKey() {

Runtime/material/slider_theme.cs

                 outlinePaint.strokeWidth = 1.0f;
                 canvas.drawRect(valueRect, outlinePaint);
                 return true;
+#pragma warning restore 0162
             });
 
             _addArc(

Runtime/painting/fractional_offset.cs

         public static readonly FractionalOffset bottomCenter = new FractionalOffset(0.5f, 1.0f);
 
         public static readonly FractionalOffset bottomRight = new FractionalOffset(1.0f, 1.0f);
+#pragma warning restore 0108
 
         public static Alignment operator -(FractionalOffset a, Alignment b) {
             if (!(b is FractionalOffset)) {

Runtime/rendering/object.mixin.gen.cs

 namespace Unity.UIWidgets.rendering {
 
     public abstract class RenderObjectWithChildMixinRenderObject<ChildType> : RenderObject, RenderObjectWithChildMixin<ChildType>, RenderObjectWithChildMixin where ChildType : RenderObject {
-        public bool debugValidateChild(RenderObject child) {
+        public virtual bool debugValidateChild(RenderObject child) {
             D.assert(() => {
                 if (!(child is ChildType)) {
                     throw new UIWidgetsError(
 
 
     public abstract class RenderObjectWithChildMixinRenderBox<ChildType> : RenderBox, RenderObjectWithChildMixin<ChildType>, RenderObjectWithChildMixin where ChildType : RenderObject {
-        public bool debugValidateChild(RenderObject child) {
+        public virtual bool debugValidateChild(RenderObject child) {
             D.assert(() => {
                 if (!(child is ChildType)) {
                     throw new UIWidgetsError(
             get { return this._childCount; }
         }
 
-        public new bool debugValidateChild(RenderObject child) {
+        public override bool debugValidateChild(RenderObject child) {
             D.assert(() => {
                 if (!(child is ChildType)) {
                     throw new UIWidgetsError(

Runtime/rendering/paragraph.cs

 
 #pragma warning disable 0414
         bool _pointerHoverInside;
+#pragma warning restore 0414
         bool _hasHoverRecognizer;
         MouseTrackerAnnotation _hoverAnnotation;
 

Tests/Editor/SceneViewTests.cs

             onPreSceneGUIDelegate += OnPreSceneGUI;
 #pragma warning disable 0618
             SceneView.onSceneGUIDelegate += OnSceneGUI;
+#pragma warning restore 0618
             EditorApplication.update += Update;
 
             SceneView.RepaintAll();
             onPreSceneGUIDelegate -= OnPreSceneGUI;
 #pragma warning disable 0618
             SceneView.onSceneGUIDelegate -= OnSceneGUI;
+#pragma warning restore 0618
             EditorApplication.update -= Update;
             SceneView.RepaintAll();
         }
                 field.SetValue(null, value);
             }
         }
+#pragma warning restore 0618
 
         static Func<Widget>[] _options;
 

Tests/Editor/Widgets.cs

         float _offsetY = 0.0f;
 #pragma warning disable 0414
         int _index = -1;
+#pragma warning restore 0414
 
         Widget _buildHeader(BuildContext context) {
             return new Container(