Add static text trait to plain semantics object with label in iOS

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

@@ -530,6 +530,11 @@ - (UIAccessibilityTraits)accessibilityTraits {
   if ([self node].HasFlag(flutter::SemanticsFlags::kIsLink)) {
     traits |= UIAccessibilityTraitLink;
   }
+  if (traits == UIAccessibilityTraitNone &&
+      [[self accessibilityLabel] length] != 0 &&
+      ![self node].HasFlag(flutter::SemanticsFlags::kIsTextField)) {
+    traits = UIAccessibilityTraitStaticText;
+  }
   return traits;
 }
 

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

@@ -89,6 +89,17 @@ - (void)testReplaceChildAtIndex {
   XCTAssertEqualObjects(parent.children, @[ child2 ]);
 }
 
+- (void)testPlainSemanticsObjectWithLabelHasStaticTextTrait {
+  fml::WeakPtrFactory<flutter::AccessibilityBridgeIos> factory(
+      new flutter::MockAccessibilityBridge());
+  fml::WeakPtr<flutter::AccessibilityBridgeIos> bridge = factory.GetWeakPtr();
+  flutter::SemanticsNode node;
+  node.label = "foo";
+  FlutterSemanticsObject* object = [[FlutterSemanticsObject alloc] initWithBridge:bridge uid:0];
+  [object setSemanticsNode:&node];
+  XCTAssertEqual([object accessibilityTraits], UIAccessibilityTraitStaticText);
+}
+
 - (void)testShouldTriggerAnnouncement {
   fml::WeakPtrFactory<flutter::AccessibilityBridgeIos> factory(
       new flutter::MockAccessibilityBridge());