[web] @JS('Intl') (flutter/engine#39211)

* [web] @JS('Intl')

* Fix call sites

* one more place

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

@@ -63,9 +63,6 @@ extension DomWindowExtension on DomWindow {
   /// The Trusted Types API (when available).
   /// See: https://developer.mozilla.org/en-US/docs/Web/API/Trusted_Types_API
   external DomTrustedTypePolicyFactory? get trustedTypes;
-
-  // ignore: non_constant_identifier_names
-  external DomIntl get Intl;
 }
 
 typedef DomRequestAnimationFrameCallback = void Function(num highResTime);
@@ -83,6 +80,9 @@ extension DomConsoleExtension on DomConsole {
 @JS('window')
 external DomWindow get domWindow;
 
+@JS('Intl')
+external DomIntl get domIntl;
+
 @JS()
 @staticInterop
 class DomNavigator {}
@@ -1815,7 +1815,7 @@ extension DomV8BreakIteratorExtension on DomV8BreakIterator {
 }
 
 DomV8BreakIterator createV8BreakIterator() {
-  final Object? v8BreakIterator = domWindow.Intl.v8BreakIterator;
+  final Object? v8BreakIterator = domIntl.v8BreakIterator;
   if (v8BreakIterator == null) {
     throw UnimplementedError('v8BreakIterator is not supported.');
   }

engine/src/flutter/lib/web_ui/lib/src/engine/text/line_breaker.dart

@@ -42,7 +42,7 @@ enum LineBreakType {
 /// Splits [text] into fragments based on line breaks.
 abstract class LineBreakFragmenter extends TextFragmenter {
   factory LineBreakFragmenter(String text) {
-    if (domWindow.Intl.v8BreakIterator != null) {
+    if (domIntl.v8BreakIterator != null) {
       return V8LineBreakFragmenter(text);
     }
     return FWLineBreakFragmenter(text);
@@ -66,7 +66,7 @@ class FWLineBreakFragmenter extends TextFragmenter implements LineBreakFragmente
 /// `v8BreakIterator` API to find line breaks in the given [text].
 class V8LineBreakFragmenter extends TextFragmenter implements LineBreakFragmenter {
   V8LineBreakFragmenter(super.text)
-      : assert(domWindow.Intl.v8BreakIterator != null);
+      : assert(domIntl.v8BreakIterator != null);
 
   @override
   List<LineBreakFragment> fragment() {

engine/src/flutter/lib/web_ui/test/text/line_breaker_test.dart

@@ -421,7 +421,7 @@ void groupForEachFragmenter(GroupBody callback) {
     () => callback(isV8: false),
   );
 
-  if (domWindow.Intl.v8BreakIterator != null) {
+  if (domIntl.v8BreakIterator != null) {
     group(
       '$V8LineBreakFragmenter',
       () => callback(isV8: true),