Fix Chip highlight color isn't drawn on top of the background color (#124673)

packages/flutter/lib/src/material/chip.dart

@@ -14,6 +14,7 @@ import 'colors.dart';
 import 'constants.dart';
 import 'debug.dart';
 import 'icons.dart';
+import 'ink_decoration.dart';
 import 'ink_well.dart';
 import 'material.dart';
 import 'material_localizations.dart';
@@ -1210,7 +1211,7 @@ class _RawChipState extends State<RawChip> with MaterialStateMixin, TickerProvid
         child: AnimatedBuilder(
           animation: Listenable.merge(<Listenable>[selectController, enableController]),
           builder: (BuildContext context, Widget? child) {
-            return Container(
+            return Ink(
               decoration: ShapeDecoration(
                 shape: resolvedShape,
                 color: _getBackgroundColor(theme, chipTheme, chipDefaults),

packages/flutter/test/material/chip_test.dart

@@ -57,7 +57,7 @@ dynamic getRenderChip(WidgetTester tester) {
   if (!tester.any(findRenderChipElement())) {
     return null;
   }
-  final Element element = tester.element(findRenderChipElement());
+  final Element element = tester.element(findRenderChipElement().first);
   return element.renderObject;
 }
 
@@ -3284,6 +3284,55 @@ void main() {
 
     expect(tester.takeException(), isNull);
   });
+
+  testWidgets('Chip background color and shape are drawn on Ink', (WidgetTester tester) async {
+    const Color backgroundColor = Color(0xff00ff00);
+    const OutlinedBorder shape = ContinuousRectangleBorder();
+
+    await tester.pumpWidget(wrapForChip(
+      child: const RawChip(
+        label: Text('text'),
+        backgroundColor: backgroundColor,
+        shape: shape,
+      ),
+    ));
+
+    final Ink ink = tester.widget(find.descendant(
+      of: find.byType(RawChip),
+      matching: find.byType(Ink),
+    ));
+    final ShapeDecoration decoration = ink.decoration! as ShapeDecoration;
+    expect(decoration.color, backgroundColor);
+    expect(decoration.shape, shape);
+  });
+
+  testWidgets('Chip highlight color is drawn on top of the backgroundColor', (WidgetTester tester) async {
+    final FocusNode focusNode = FocusNode(debugLabel: 'RawChip');
+    tester.binding.focusManager.highlightStrategy = FocusHighlightStrategy.alwaysTraditional;
+    const Color backgroundColor = Color(0xff00ff00);
+
+    await tester.pumpWidget(wrapForChip(
+      child: RawChip(
+        label: const Text('text'),
+        backgroundColor: backgroundColor,
+        autofocus: true,
+        focusNode: focusNode,
+        onPressed: () {},
+      ),
+    ));
+
+    await tester.pumpAndSettle();
+
+    expect(focusNode.hasPrimaryFocus, isTrue);
+    expect(
+      find.byType(Material).last,
+      paints
+        // Background color is drawn first.
+        ..rrect(color: backgroundColor)
+        // Highlight color is drawn on top of the background color.
+        ..rect(color: const Color(0x1f000000)),
+    );
+  });
 }
 
 class _MaterialStateOutlinedBorder extends StadiumBorder implements MaterialStateOutlinedBorder {