Migrate 104-complete to NNBD

mdc_100_series/lib/backdrop.dart

@@ -77,7 +77,7 @@ class _BackdropTitle extends AnimatedWidget {
     final Animation<double> animation = _listenable;
 
     return DefaultTextStyle(
-      style: Theme.of(context)!.primaryTextTheme.headline6!,
+      style: Theme.of(context).primaryTextTheme.headline6!,
       softWrap: false,
       overflow: TextOverflow.ellipsis,
       child: Row(children: <Widget>[

mdc_100_series/lib/category_menu_page.dart

@@ -31,7 +31,7 @@ class CategoryMenuPage extends StatelessWidget {
   Widget _buildCategory(Category category, BuildContext context) {
     final categoryString =
         category.toString().replaceAll('Category.', '').toUpperCase();
-    final ThemeData theme = Theme.of(context)!;
+    final ThemeData theme = Theme.of(context);
     return GestureDetector(
       onTap: () => onCategoryTap(category),
       child: category == currentCategory

mdc_100_series/lib/login.dart

@@ -39,7 +39,7 @@ class _LoginPageState extends State<LoginPage> {
                 SizedBox(height: 16.0),
                 Text(
                   'SHRINE',
-                  style: Theme.of(context)!.textTheme.headline5,
+                  style: Theme.of(context).textTheme.headline5,
                 ),
               ],
             ),
@@ -106,7 +106,7 @@ class AccentColorOverride extends StatelessWidget {
   Widget build(BuildContext context) {
     return Theme(
       child: child,
-      data: Theme.of(context)!.copyWith(
+      data: Theme.of(context).copyWith(
         accentColor: color,
         brightness: Brightness.dark,
       ),

mdc_100_series/lib/supplemental/asymmetric_view.dart

@@ -36,7 +36,7 @@ class AsymmetricView extends StatelessWidget {
     /// helpers for creating the index of the product list that will correspond
     /// to the index of the list of columns.
     return List.generate(_listItemCount(products.length), (int index) {
-      double width = .59 * MediaQuery.of(context)!.size.width;
+      double width = .59 * MediaQuery.of(context).size.width;
       Widget column;
       if (index % 2 == 0) {
         /// Even cases

mdc_100_series/lib/supplemental/product_card.dart

@@ -30,7 +30,7 @@ class ProductCard extends StatelessWidget {
   Widget build(BuildContext context) {
     final NumberFormat formatter = NumberFormat.simpleCurrency(
         decimalDigits: 0, locale: Localizations.localeOf(context).toString());
-    final ThemeData theme = Theme.of(context)!;
+    final ThemeData theme = Theme.of(context);
 
     final imageWidget = Image.asset(
       product.assetName,
@@ -47,7 +47,7 @@ class ProductCard extends StatelessWidget {
           child: imageWidget,
         ),
         SizedBox(
-          height: kTextBoxHeight * MediaQuery.of(context)!.textScaleFactor,
+          height: kTextBoxHeight * MediaQuery.of(context).textScaleFactor,
           width: 121.0,
           child: Column(
             mainAxisAlignment: MainAxisAlignment.end,

mdc_100_series/pubspec.yaml

@@ -2,12 +2,12 @@ name: Shrine
 description: Take your design up a notch and learn to use our advanced component backdrop menu.
 
 environment:
-  sdk: '>=2.10.0-56.0.dev <2.11.0'
+  sdk: '>=2.12.0-0 <3.0.0'
 
 dependencies:
   flutter:
     sdk: flutter
-  intl: ">=0.17.0-nullsafety.1 <1.0.0"
+  intl: ^0.17.0-nullsafety.2
 
   cupertino_icons: ^0.1.0
   shrine_images: 1.1.1