diff --git a/testing/dart/compositing_test.dart b/testing/dart/compositing_test.dart
index 5d8df518c278e..08aa9b84f0822 100644
--- a/testing/dart/compositing_test.dart
+++ b/testing/dart/compositing_test.dart
@@ -326,7 +326,7 @@ void main() {
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer oldLayer) {
-      return builder.pushPhysicalShape(path: Path(), color: const Color.fromARGB(0, 0, 0, 0), oldLayer: oldLayer as PhysicalShapeEngineLayer);
+      return builder.pushPhysicalShape(path: Path(), color: const Color.fromARGB(0, 0, 0, 0), oldLayer: oldLayer as PhysicalShapeEngineLayer, elevation: 0.0);
     });
     testNoSharing((SceneBuilder builder, EngineLayer oldLayer) {
       return builder.pushColorFilter(
diff --git a/testing/scenario_app/lib/src/locale_initialization.dart b/testing/scenario_app/lib/src/locale_initialization.dart
index 4a343ff9140d8..8e48a91b7c503 100644
--- a/testing/scenario_app/lib/src/locale_initialization.dart
+++ b/testing/scenario_app/lib/src/locale_initialization.dart
@@ -60,9 +60,16 @@ class LocaleInitialization extends Scenario {
         currentValueLength: 0,
         scrollChildren: 0,
         scrollIndex: 0,
+        scrollPosition: 0.0,
+        scrollExtentMax: 0.0,
+        scrollExtentMin: 0.0,
         transform: Matrix4.identity().storage,
         elevation: 0.0,
         thickness: 0.0,
+        hint: '',
+        value: '',
+        increasedValue: '',
+        decreasedValue: '',
         childrenInTraversalOrder: Int32List(0),
         childrenInHitTestOrder: Int32List(0),
         additionalActions: Int32List(0),
@@ -101,9 +108,16 @@ class LocaleInitialization extends Scenario {
         currentValueLength: 0,
         scrollChildren: 0,
         scrollIndex: 0,
+        scrollPosition: 0.0,
+        scrollExtentMax: 0.0,
+        scrollExtentMin: 0.0,
         transform: Matrix4.identity().storage,
         elevation: 0.0,
         thickness: 0.0,
+        hint: '',
+        value: '',
+        increasedValue: '',
+        decreasedValue: '',
         childrenInTraversalOrder: Int32List(0),
         childrenInHitTestOrder: Int32List(0),
         additionalActions: Int32List(0),
diff --git a/testing/scenario_app/lib/src/platform_echo_mixin.dart b/testing/scenario_app/lib/src/platform_echo_mixin.dart
index 407816c18aa35..fbd67338f5bff 100644
--- a/testing/scenario_app/lib/src/platform_echo_mixin.dart
+++ b/testing/scenario_app/lib/src/platform_echo_mixin.dart
@@ -8,6 +8,7 @@ import 'dart:ui';
 
 import 'scenario.dart';
 
+/// Echo platform messages back to the sender.
 mixin PlatformEchoMixin on Scenario {
   @override
   void onPlatformMessage(
diff --git a/testing/scenario_app/lib/src/send_text_focus_semantics.dart b/testing/scenario_app/lib/src/send_text_focus_semantics.dart
index 577331be1131c..9b5839212d99f 100644
--- a/testing/scenario_app/lib/src/send_text_focus_semantics.dart
+++ b/testing/scenario_app/lib/src/send_text_focus_semantics.dart
@@ -55,9 +55,16 @@ class SendTextFocusScemantics extends Scenario {
         currentValueLength: 0,
         scrollChildren: 0,
         scrollIndex: 0,
+        scrollPosition: 0.0,
+        scrollExtentMax: 0.0,
+        scrollExtentMin: 0.0,
         transform: Matrix4.identity().storage,
         elevation: 0.0,
         thickness: 0.0,
+        hint: '',
+        value: '',
+        increasedValue: '',
+        decreasedValue: '',
         childrenInTraversalOrder: Int32List(0),
         childrenInHitTestOrder: Int32List(0),
         additionalActions: Int32List(0),
@@ -105,9 +112,16 @@ class SendTextFocusScemantics extends Scenario {
         currentValueLength: 0,
         scrollChildren: 0,
         scrollIndex: 0,
+        scrollPosition: 0.0,
+        scrollExtentMax: 0.0,
+        scrollExtentMin: 0.0,
         transform: Matrix4.identity().storage,
         elevation: 0.0,
         thickness: 0.0,
+        hint: '',
+        value: '',
+        increasedValue: '',
+        decreasedValue: '',
         childrenInTraversalOrder: Int32List(0),
         childrenInHitTestOrder: Int32List(0),
         additionalActions: Int32List(0),