Make the InkResponse's focus highlight honor the radius parameter (#59117)

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

@@ -41,6 +41,7 @@ class InkHighlight extends InteractiveInkFeature {
     @required Color color,
     @required TextDirection textDirection,
     BoxShape shape = BoxShape.rectangle,
+    double radius,
     BorderRadius borderRadius,
     ShapeBorder customBorder,
     RectCallback rectCallback,
@@ -51,6 +52,7 @@ class InkHighlight extends InteractiveInkFeature {
        assert(textDirection != null),
        assert(fadeDuration != null),
        _shape = shape,
+       _radius = radius,
        _borderRadius = borderRadius ?? BorderRadius.zero,
        _customBorder = customBorder,
        _textDirection = textDirection,
@@ -69,6 +71,7 @@ class InkHighlight extends InteractiveInkFeature {
   }
 
   final BoxShape _shape;
+  final double _radius;
   final BorderRadius _borderRadius;
   final ShapeBorder _customBorder;
   final RectCallback _rectCallback;
@@ -112,7 +115,7 @@ class InkHighlight extends InteractiveInkFeature {
     }
     switch (_shape) {
       case BoxShape.circle:
-        canvas.drawCircle(rect.center, Material.defaultSplashRadius, paint);
+        canvas.drawCircle(rect.center, _radius ?? Material.defaultSplashRadius, paint);
         break;
       case BoxShape.rectangle:
         if (_borderRadius != BorderRadius.zero) {

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

@@ -840,6 +840,7 @@ class _InkResponseState extends State<_InkResponseStateWidget>
           referenceBox: referenceBox,
           color: getHighlightColorForType(type),
           shape: widget.highlightShape,
+          radius: widget.radius,
           borderRadius: widget.borderRadius,
           customBorder: widget.customBorder,
           rectCallback: widget.getRectCallback(referenceBox),

packages/flutter/test/material/ink_well_test.dart

@@ -313,6 +313,36 @@ void main() {
     await gesture.up();
   });
 
+  testWidgets('ink response uses radius for focus highlight', (WidgetTester tester) async {
+    FocusManager.instance.highlightStrategy = FocusHighlightStrategy.alwaysTraditional;
+    final FocusNode focusNode = FocusNode(debugLabel: 'Ink Focus');
+    await tester.pumpWidget(
+      Material(
+        child: Directionality(
+          textDirection: TextDirection.ltr,
+          child: Center(
+            child: Container(
+              width: 100,
+              height: 100,
+              child: InkResponse(
+                focusNode: focusNode,
+                radius: 20,
+                focusColor: const Color(0xff0000ff),
+                onTap: () { },
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+    final RenderObject inkFeatures = tester.allRenderObjects.firstWhere((RenderObject object) => object.runtimeType.toString() == '_RenderInkFeatures');
+    expect(inkFeatures, paintsExactlyCountTimes(#drawCircle, 0));
+    focusNode.requestFocus();
+    await tester.pumpAndSettle();
+    expect(inkFeatures, paints..circle(radius: 20, color: const Color(0xff0000ff)));
+  });
+
   testWidgets("ink response doesn't change color on focus when on touch device", (WidgetTester tester) async {
     FocusManager.instance.highlightStrategy = FocusHighlightStrategy.alwaysTouch;
     final FocusNode focusNode = FocusNode(debugLabel: 'Ink Focus');