[WebParagraph] Fix a property name on newer Chrome versions (#173477)

engine/src/flutter/lib/web_ui/lib/src/engine/dom.dart

diff --git a/engine/src/flutter/lib/web_ui/lib/src/engine/dom.dart b/engine/src/flutter/lib/web_ui/lib/src/engine/dom.dart
index 3939217..dea6678 100644
--- a/engine/src/flutter/lib/web_ui/lib/src/engine/dom.dart
+++ b/engine/src/flutter/lib/web_ui/lib/src/engine/dom.dart
@@ -2607,9 +2607,16 @@
 
 @JS('TextCluster')
 extension type DomTextCluster._(JSObject _) implements JSObject {
-  // TODO(jlavrova): This has been renamed to `start` in the spec.
-  // See: https://github.com/fserb/canvas2D/blob/master/spec/enhanced-textmetrics.md
-  external int get begin;
+  @JS('begin')
+  external int? _begin;
+  @JS('start')
+  external int _start;
+  // The proposal had this `begin` then renamed it to `start`. Some versions of Chrome still have
+  // the old name.
+  //
+  // `_begin` can be removed once this feature is launched in a stable Chrome release.
+  int get start => _begin ?? _start;
+
   external int get end;
   external double get x;
   external double get y;

engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/layout.dart

diff --git a/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/layout.dart b/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/layout.dart
index b90b4dd..7a11af7 100644
--- a/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/layout.dart
+++ b/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/layout.dart
@@ -60,7 +60,7 @@
       final DomTextMetrics blockTextMetrics = layoutContext.measureText(text);
       for (final DomTextCluster cluster in blockTextMetrics.getTextClusters()) {
         final List<DomRectReadOnly> rects = blockTextMetrics.getSelectionRects(
-          cluster.begin,
+          cluster.start,
           cluster.end,
         );
         final ui.Rect bounds = ui.Rect.fromLTWH(
@@ -69,7 +69,7 @@
           rects.first.width,
           rects.first.height,
         );
-        for (int i = cluster.begin; i < cluster.end; i += 1) {
+        for (int i = cluster.start; i < cluster.end; i += 1) {
           textToClusterMap[i] = textClusters.length;
         }
         textClusters.add(ExtendedTextCluster(cluster, bounds, blockTextMetrics));
@@ -288,7 +288,7 @@
 
 class ExtendedTextCluster {
   ExtendedTextCluster(this.cluster, this.bounds, this.textMetrics)
-    : start = cluster!.begin,
+    : start = cluster!.start,
       end = cluster.end;
 
   // TODO(jlavrova): Remove this.

engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/paragraph.dart

diff --git a/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/paragraph.dart b/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/paragraph.dart
index a6ef5fef..5ae8434 100644
--- a/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/paragraph.dart
+++ b/engine/src/flutter/lib/web_ui/lib/src/engine/web_paragraph/paragraph.dart
@@ -7,7 +7,6 @@
 
 import '../canvaskit/canvaskit_canvas.dart';
 import '../dom.dart';
-import '../util.dart';
 import 'debug.dart';
 import 'layout.dart';
 import 'paint.dart';
@@ -307,16 +306,7 @@
 
   @override
   void layout(ui.ParagraphConstraints constraints) {
-    try {
-      _layout.performLayout(constraints.width);
-    } catch (e) {
-      printWarning(
-        'Canvas 2D threw an exception while laying '
-        'out the paragraph. '
-        'Exception:\n$e',
-      );
-      rethrow;
-    }
+    _layout.performLayout(constraints.width);
   }
 
   /// Paints this paragraph instance on a [canvas] at the given [offset].