Add some debug properties to BackdropFilterLayer (#101101)

packages/flutter/lib/src/rendering/layer.dart

@@ -1897,7 +1897,7 @@ class ShaderMaskLayer extends ContainerLayer {
     super.debugFillProperties(properties);
     properties.add(DiagnosticsProperty<Shader>('shader', shader));
     properties.add(DiagnosticsProperty<Rect>('maskRect', maskRect));
-    properties.add(DiagnosticsProperty<BlendMode>('blendMode', blendMode));
+    properties.add(EnumProperty<BlendMode>('blendMode', blendMode));
   }
 }
 
@@ -1956,6 +1956,13 @@ class BackdropFilterLayer extends ContainerLayer {
     addChildrenToScene(builder);
     builder.pop();
   }
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    properties.add(DiagnosticsProperty<ui.ImageFilter>('filter', filter));
+    properties.add(EnumProperty<BlendMode>('blendMode', blendMode));
+  }
 }
 
 /// A composited layer that uses a physical model to producing lighting effects.

packages/flutter/test/rendering/layers_test.dart

@@ -365,6 +365,14 @@ void main() {
     );
   });
 
+  test('BackdropFilterLayer prints filter and blendMode in debug info', () {
+    final ImageFilter filter = ImageFilter.blur(sigmaX: 1.0, sigmaY: 1.0, tileMode: TileMode.repeated);
+    final BackdropFilterLayer layer = BackdropFilterLayer(filter: filter, blendMode: BlendMode.clear);
+    final List<String> info = _getDebugInfo(layer);
+    expect(info, contains(isBrowser ? 'filter: ImageFilter.blur(1, 1, TileMode.repeated)' : 'filter: ImageFilter.blur(1.0, 1.0, repeated)'));
+    expect(info, contains('blendMode: clear'));
+  });
+
   test('PictureLayer prints picture, raster cache hints in debug info', () {
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);