[Skwasm] Forward text height from paragraph height to default text style (#51819)

We need to apply the paragraph style's height to the initial default text style on the stack. I also added a `toString` method for `StrutStyle` so that things are a bit easier to debug.

Author: eyebrowsoffire

lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paragraph.dart

@@ -681,6 +681,31 @@ final class SkwasmStrutStyle extends SkwasmObjectWrapper<RawStrutStyle> implemen
       _forceStrutHeight,
     );
   }
+
+  @override
+  String toString() {
+    String result = super.toString();
+    assert(() {
+      final List<String>? fontFamilyFallback = _fontFamilyFallback;
+      final double? fontSize = _fontSize;
+      final double? height = _height;
+      final double? leading = _leading;
+      result = 'StrutStyle('
+          'fontFamily: ${_fontFamily ?? "unspecified"}, '
+          'fontFamilyFallback: ${_fontFamilyFallback ?? "unspecified"}, '
+          'fontFamilyFallback: ${fontFamilyFallback != null && fontFamilyFallback.isNotEmpty ? fontFamilyFallback : "unspecified"}, '
+          'fontSize: ${fontSize != null ? fontSize.toStringAsFixed(1) : "unspecified"}, '
+          'height: ${height != null ? "${height.toStringAsFixed(1)}x" : "unspecified"}, '
+          'leading: ${leading != null ? "${leading.toStringAsFixed(1)}x" : "unspecified"}, '
+          'fontWeight: ${_fontWeight ?? "unspecified"}, '
+          'fontStyle: ${_fontStyle ?? "unspecified"}, '
+          'forceStrutHeight: ${_forceStrutHeight ?? "unspecified"}, '
+          'leadingDistribution: ${_leadingDistribution ?? "unspecified"}, '
+          ')';
+      return true;
+    }());
+    return result;
+  }
 }
 
 class SkwasmParagraphStyle extends SkwasmObjectWrapper<RawParagraphStyle> implements ui.ParagraphStyle {
@@ -741,6 +766,9 @@ class SkwasmParagraphStyle extends SkwasmObjectWrapper<RawParagraphStyle> implem
     if (fontSize != null) {
       textStyleSetFontSize(textStyleHandle, fontSize);
     }
+    if (height != null) {
+      textStyleSetHeight(textStyleHandle, height);
+    }
     if (fontWeight != null || fontStyle != null) {
       fontWeight ??= ui.FontWeight.normal;
       fontStyle ??= ui.FontStyle.normal;

lib/web_ui/test/ui/line_metrics_test.dart

@@ -57,6 +57,20 @@ Future<void> testMain() async {
     expect(paragraph.getLineMetricsAt(7), isNull);
   });
 
+  test('respects paragraph height', () {
+    final ui.ParagraphBuilder builder = ui.ParagraphBuilder(ui.ParagraphStyle(
+      fontSize: 10,
+      height: 1.5,
+    ))..addText('A' * 10);
+    final ui.Paragraph paragraph = builder.build();
+    paragraph.layout(const ui.ParagraphConstraints(width: double.infinity));
+
+    expect(paragraph.numberOfLines, 1);
+    final ui.LineMetrics? metrics = paragraph.getLineMetricsAt(0);
+    expect(metrics, isNotNull);
+    expect(metrics!.height, 15);
+  });
+
   test('Basic glyph metrics', () {
     const double fontSize = 10;
     final ui.ParagraphBuilder builder = ui.ParagraphBuilder(ui.ParagraphStyle(