diff --git a/lib/codeviewer/code_segments.dart b/lib/codeviewer/code_segments.dart
index f7dd1a864a..65d753d3ee 100644
--- a/lib/codeviewer/code_segments.dart
+++ b/lib/codeviewer/code_segments.dart
@@ -37180,20 +37180,6 @@ class CodeSegments {
       TextSpan(style: codeStyle.baseStyle, text: ' '),
       TextSpan(style: codeStyle.punctuationStyle, text: '{'),
       TextSpan(style: codeStyle.baseStyle, text: '\u000a  '),
-      TextSpan(style: codeStyle.keywordStyle, text: 'final'),
-      TextSpan(style: codeStyle.baseStyle, text: ' '),
-      TextSpan(style: codeStyle.classStyle, text: 'GlobalKey'),
-      TextSpan(style: codeStyle.punctuationStyle, text: '<'),
-      TextSpan(style: codeStyle.classStyle, text: 'ScaffoldState'),
-      TextSpan(style: codeStyle.punctuationStyle, text: '>'),
-      TextSpan(style: codeStyle.baseStyle, text: ' _scaffoldKey '),
-      TextSpan(style: codeStyle.punctuationStyle, text: '='),
-      TextSpan(style: codeStyle.baseStyle, text: ' '),
-      TextSpan(style: codeStyle.classStyle, text: 'GlobalKey'),
-      TextSpan(style: codeStyle.punctuationStyle, text: '<'),
-      TextSpan(style: codeStyle.classStyle, text: 'ScaffoldState'),
-      TextSpan(style: codeStyle.punctuationStyle, text: '>();'),
-      TextSpan(style: codeStyle.baseStyle, text: '\u000a\u000a  '),
       TextSpan(style: codeStyle.classStyle, text: 'PersonData'),
       TextSpan(style: codeStyle.baseStyle, text: ' person '),
       TextSpan(style: codeStyle.punctuationStyle, text: '='),
@@ -37619,10 +37605,6 @@ class CodeSegments {
       TextSpan(style: codeStyle.baseStyle, text: ' '),
       TextSpan(style: codeStyle.classStyle, text: 'Scaffold'),
       TextSpan(style: codeStyle.punctuationStyle, text: '('),
-      TextSpan(style: codeStyle.baseStyle, text: '\u000a      key'),
-      TextSpan(style: codeStyle.punctuationStyle, text: ':'),
-      TextSpan(style: codeStyle.baseStyle, text: ' _scaffoldKey'),
-      TextSpan(style: codeStyle.punctuationStyle, text: ','),
       TextSpan(style: codeStyle.baseStyle, text: '\u000a      body'),
       TextSpan(style: codeStyle.punctuationStyle, text: ':'),
       TextSpan(style: codeStyle.baseStyle, text: ' '),
diff --git a/lib/demos/material/menu_demo.dart b/lib/demos/material/menu_demo.dart
index b1fc285d7f..cb4a151682 100644
--- a/lib/demos/material/menu_demo.dart
+++ b/lib/demos/material/menu_demo.dart
@@ -36,8 +36,6 @@ class MenuDemo extends StatefulWidget {
 }
 
 class _MenuDemoState extends State<MenuDemo> {
-  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
-
   void showInSnackBar(String value) {
     ScaffoldMessenger.of(context).hideCurrentSnackBar();
     ScaffoldMessenger.of(context).showSnackBar(SnackBar(
@@ -64,7 +62,6 @@ class _MenuDemoState extends State<MenuDemo> {
     }
 
     return Scaffold(
-      key: _scaffoldKey,
       appBar: AppBar(
         title: Text(GalleryLocalizations.of(context).demoMenuTitle),
         automaticallyImplyLeading: false,
diff --git a/lib/demos/material/text_field_demo.dart b/lib/demos/material/text_field_demo.dart
index 26116171c0..a5c454a928 100644
--- a/lib/demos/material/text_field_demo.dart
+++ b/lib/demos/material/text_field_demo.dart
@@ -102,8 +102,6 @@ class _PasswordFieldState extends State<PasswordField> {
 }
 
 class TextFormFieldDemoState extends State<TextFormFieldDemo> {
-  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
-
   PersonData person = PersonData();
 
   void showInSnackBar(String value) {
@@ -172,7 +170,6 @@ class TextFormFieldDemoState extends State<TextFormFieldDemo> {
     const sizedBoxSpace = SizedBox(height: 24);
 
     return Scaffold(
-      key: _scaffoldKey,
       body: Form(
         key: _formKey,
         autovalidateMode: _autoValidateMode,
diff --git a/lib/pages/demo.dart b/lib/pages/demo.dart
index d0f7da5bc6..3b21614230 100644
--- a/lib/pages/demo.dart
+++ b/lib/pages/demo.dart
@@ -63,10 +63,11 @@ class _DemoPageState extends State<DemoPage> {
       // Return to root if invalid slug.
       Navigator.of(context).pop();
     }
-    return GalleryDemoPage(
+    return ScaffoldMessenger(
+        child: GalleryDemoPage(
       restorationId: widget.slug,
       demo: slugToDemoMap[widget.slug],
-    );
+    ));
   }
 }
 
@@ -382,9 +383,11 @@ class _GalleryDemoPageState extends State<GalleryDemoPage>
     }
 
     Widget body;
-    Widget demoContent = DemoContent(
-      height: contentHeight,
-      buildRoute: _currentConfig.buildRoute,
+    Widget demoContent = ScaffoldMessenger(
+      child: DemoContent(
+        height: contentHeight,
+        buildRoute: _currentConfig.buildRoute,
+      ),
     );
     if (isDesktop) {
       final isFullScreen = currentDemoState == _DemoState.fullscreen;
diff --git a/pubspec.lock b/pubspec.lock
index 1119f72872..38862b5a01 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -658,7 +658,7 @@ packages:
       name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.2.0"
+    version: "5.5.0"
   watcher:
     dependency: transitive
     description: