Eliminate direct access of Typography.black/white in manual tests (#6640)

dev/manual_tests/card_collection.dart

@@ -32,8 +32,6 @@ class CardCollectionState extends State<CardCollection> {
   static const double kCardMargins = 8.0;
   static const double kFixedCardHeight = 100.0;
 
-  final TextStyle backgroundTextStyle = Typography.white.title;
-
   Map<int, Color> _primaryColor = Colors.deepPurple;
   List<CardModel> _cardModels;
   DismissDirection _dismissDirection = DismissDirection.horizontal;
@@ -358,6 +356,9 @@ class CardCollectionState extends State<CardCollection> {
     if (_dismissDirection == DismissDirection.endToStart)
       rightArrowIcon = new Opacity(opacity: 0.1, child: rightArrowIcon);
 
+    final ThemeData theme = Theme.of(context);
+    final TextStyle backgroundTextStyle = theme.primaryTextTheme.title;
+
     // The background Widget appears behind the Dismissable card when the card
     // moves to the left or right. The Positioned widget ensures that the
     // size of the background,card Stack will be based only on the card. The
@@ -369,7 +370,7 @@ class CardCollectionState extends State<CardCollection> {
         child: new Viewport(
           child: new Container(
             height: cardModel.height,
-            decoration: new BoxDecoration(backgroundColor: Theme.of(context).primaryColor),
+            decoration: new BoxDecoration(backgroundColor: theme.primaryColor),
             child: new Row(
               children: <Widget>[
                 leftArrowIcon,

dev/manual_tests/drag_and_drop.dart

@@ -186,7 +186,7 @@ class MovableBall extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     Widget ball = new DefaultTextStyle(
-      style: Typography.white.body1,
+      style: Theme.of(context).primaryTextTheme.body1,
       textAlign: TextAlign.center,
       child: new Dot(
         key: kBallKey,

dev/manual_tests/raw_keyboard.dart

@@ -41,6 +41,7 @@ class _HardwareKeyDemoState extends State<RawKeyboardDemo> {
 
   @override
   Widget build(BuildContext context)  {
+    final TextTheme textTheme = Theme.of(context).textTheme;
     bool focused = Focus.at(context);
     Widget child;
     if (!focused) {
@@ -49,12 +50,12 @@ class _HardwareKeyDemoState extends State<RawKeyboardDemo> {
           Focus.moveTo(config.key);
         },
         child: new Center(
-          child: new Text('Tap to focus', style: Typography.black.display1),
+          child: new Text('Tap to focus', style: textTheme.display1),
         ),
       );
     } else if (_event == null) {
       child = new Center(
-        child: new Text('Press a key', style: Typography.black.display1),
+        child: new Text('Press a key', style: textTheme.display1),
       );
     } else {
       int codePoint;
@@ -67,9 +68,9 @@ class _HardwareKeyDemoState extends State<RawKeyboardDemo> {
       child = new Column(
         mainAxisAlignment: MainAxisAlignment.center,
         children: <Widget>[
-          new Text('${_event.runtimeType}', style: Typography.black.body2),
-          new Text('codePoint: $codePoint', style: Typography.black.display4),
-          new Text('keyCode: $keyCode', style: Typography.black.display4),
+          new Text('${_event.runtimeType}', style: textTheme.body2),
+          new Text('codePoint: $codePoint', style: textTheme.display4),
+          new Text('keyCode: $keyCode', style: textTheme.display4),
         ],
       );
     }