Revert "fix On iOS, dialog titles are announced twice (#19826)"

This reverts commit 48a6fde.

Author: gaaclarke

shell/platform/darwin/ios/framework/Source/SemanticsObject.h

@@ -93,7 +93,7 @@ constexpr int32_t kRootNodeId = 0;
 - (BOOL)nodeWillCauseScroll:(const flutter::SemanticsNode*)node;
 - (BOOL)nodeShouldTriggerAnnouncement:(const flutter::SemanticsNode*)node;
 - (void)collectRoutes:(NSMutableArray<SemanticsObject*>*)edges;
-- (SemanticsObject*)routeFocusObject;
+- (NSString*)routeName;
 - (BOOL)onCustomAccessibilityAction:(FlutterCustomAccessibilityAction*)action;
 
 @end

shell/platform/darwin/ios/framework/Source/SemanticsObject.mm

@@ -282,21 +282,20 @@ - (BOOL)onCustomAccessibilityAction:(FlutterCustomAccessibilityAction*)action {
   return YES;
 }
 
-- (SemanticsObject*)routeFocusObject {
-  // Returns the first SemanticObject in this branch that has
-  // the NamesRoute flag with a non-nil semantic label. Otherwise
-  // returns nil.
+- (NSString*)routeName {
+  // Returns the first non-null and non-empty semantic label of a child
+  // with an NamesRoute flag. Otherwise returns nil.
   if ([self node].HasFlag(flutter::SemanticsFlags::kNamesRoute)) {
     NSString* newName = [self accessibilityLabel];
     if (newName != nil && [newName length] > 0) {
-      return self;
+      return newName;
     }
   }
   if ([self hasChildren]) {
     for (SemanticsObject* child in self.children) {
-      SemanticsObject* focusObject = [child routeFocusObject];
-      if (focusObject != nil) {
-        return focusObject;
+      NSString* newName = [child routeName];
+      if (newName != nil && [newName length] > 0) {
+        return newName;
       }
     }
   }

shell/platform/darwin/ios/framework/Source/accessibility_bridge.mm

@@ -197,13 +197,11 @@ void PostAccessibilityNotification(UIAccessibilityNotifications notification,
   layoutChanged = layoutChanged || [doomed_uids count] > 0;
   // We should send out only one notification per semantics update.
   if (routeChanged) {
+
     if (!ios_delegate_->IsFlutterViewControllerPresentingModalViewController(view_controller_)) {
-      SemanticsObject* nextToFocus = [lastAdded routeFocusObject];
-      if (!nextToFocus && root) {
-        nextToFocus = FindFirstFocusable(root);
-      }
+      NSString* routeName = [lastAdded routeName];
       ios_delegate_->PostAccessibilityNotification(UIAccessibilityScreenChangedNotification,
-                                                   nextToFocus);
+                                                   routeName);
     }
   } else if (layoutChanged) {
     SemanticsObject* nextToFocus = nil;

shell/platform/darwin/ios/framework/Source/accessibility_bridge_test.mm

@@ -328,9 +328,7 @@ - (void)testAnnouncesRouteChanges {
   bridge->UpdateSemantics(/*nodes=*/nodes, /*actions=*/actions);
 
   XCTAssertEqual([accessibility_notifications count], 1ul);
-  SemanticsObject* focusObject = accessibility_notifications[0][@"argument"];
-  XCTAssertEqual([focusObject uid], 3);
-  XCTAssertEqualObjects([focusObject accessibilityLabel], @"node3");
+  XCTAssertEqualObjects(accessibility_notifications[0][@"argument"], @"route");
   XCTAssertEqual([accessibility_notifications[0][@"notification"] unsignedIntValue],
                  UIAccessibilityScreenChangedNotification);
 }