[rename fixit] RouteBuilder -> BuildContext

Fixes #2353
diff --git a/dev/manual_tests/card_collection.dart b/dev/manual_tests/card_collection.dart
index dd264e4..c384317 100644
--- a/dev/manual_tests/card_collection.dart
+++ b/dev/manual_tests/card_collection.dart
@@ -462,8 +462,8 @@
 void main() {
   runApp(new MaterialApp(
     title: 'Cards',
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) => new CardCollection(),
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) => new CardCollection(),
     }
   ));
 }
diff --git a/dev/manual_tests/drag_and_drop.dart b/dev/manual_tests/drag_and_drop.dart
index 435ce6b..58daccc 100644
--- a/dev/manual_tests/drag_and_drop.dart
+++ b/dev/manual_tests/drag_and_drop.dart
@@ -283,8 +283,8 @@
 void main() {
   runApp(new MaterialApp(
     title: 'Drag and Drop Flutter Demo',
-    routes: <String, RouteBuilder>{
-     '/': (RouteArguments args) => new DragAndDropApp()
+    routes: <String, WidgetBuilder>{
+     '/': (BuildContext context) => new DragAndDropApp()
     }
   ));
 }
diff --git a/dev/manual_tests/mozart.dart b/dev/manual_tests/mozart.dart
index 4f6dd57..f8664f7 100644
--- a/dev/manual_tests/mozart.dart
+++ b/dev/manual_tests/mozart.dart
@@ -238,6 +238,6 @@
 void main() {
   runApp(new MaterialApp(
     title: 'Mozart',
-    routes: <String, RouteBuilder>{ '/': (_) => new WindowManager() }
+    routes: <String, WidgetBuilder>{ '/': (_) => new WindowManager() }
   ));
 }
diff --git a/dev/manual_tests/overlay_geometry.dart b/dev/manual_tests/overlay_geometry.dart
index aec69e5..f22472b 100644
--- a/dev/manual_tests/overlay_geometry.dart
+++ b/dev/manual_tests/overlay_geometry.dart
@@ -179,8 +179,8 @@
       accentColor: Colors.redAccent[200]
     ),
     title: 'Cards',
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) => new OverlayGeometryApp()
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) => new OverlayGeometryApp()
     }
   ));
 }
diff --git a/dev/manual_tests/pageable_list.dart b/dev/manual_tests/pageable_list.dart
index 5a71c54..9dbf328 100644
--- a/dev/manual_tests/pageable_list.dart
+++ b/dev/manual_tests/pageable_list.dart
@@ -142,8 +142,8 @@
       primarySwatch: Colors.blue,
       accentColor: Colors.redAccent[200]
     ),
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) => new PageableListApp(),
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) => new PageableListApp(),
     }
   ));
 }
diff --git a/dev/manual_tests/raw_keyboard.dart b/dev/manual_tests/raw_keyboard.dart
index 01c2c09..ea82ce1 100644
--- a/dev/manual_tests/raw_keyboard.dart
+++ b/dev/manual_tests/raw_keyboard.dart
@@ -12,8 +12,8 @@
   runApp(
     new MaterialApp(
       title: "Hardware Key Demo",
-      routes: <String, RouteBuilder>{
-        '/': (RouteArguments args) {
+      routes: <String, WidgetBuilder>{
+        '/': (BuildContext context) {
           return new Scaffold(
             toolBar: new ToolBar(
               center: new Text("Hardware Key Demo")
diff --git a/examples/layers/widgets/gestures.dart b/examples/layers/widgets/gestures.dart
index de28095..afd6301 100644
--- a/examples/layers/widgets/gestures.dart
+++ b/examples/layers/widgets/gestures.dart
@@ -214,8 +214,8 @@
 void main() {
   runApp(new MaterialApp(
     theme: new ThemeData.dark(),
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) {
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) {
         return new Scaffold(
           toolBar: new ToolBar(
               center: new Text('Gestures Demo')),
diff --git a/examples/layers/widgets/media_query.dart b/examples/layers/widgets/media_query.dart
index b58b8a7..9b4c9b4 100644
--- a/examples/layers/widgets/media_query.dart
+++ b/examples/layers/widgets/media_query.dart
@@ -97,8 +97,8 @@
 void main() {
   runApp(new MaterialApp(
     title: 'Media Query Example',
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) {
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) {
         return new Scaffold(
           toolBar: new ToolBar(
             center: new Text('Media Query Example')
diff --git a/examples/layers/widgets/sectors.dart b/examples/layers/widgets/sectors.dart
index 9800525..e368a4f 100644
--- a/examples/layers/widgets/sectors.dart
+++ b/examples/layers/widgets/sectors.dart
@@ -151,8 +151,8 @@
     return new MaterialApp(
       theme: new ThemeData.light(),
       title: 'Sector Layout',
-      routes: <String, RouteBuilder>{
-        '/': (RouteArguments args) {
+      routes: <String, WidgetBuilder>{
+        '/': (BuildContext context) {
           return new Scaffold(
             toolBar: new ToolBar(
               center: new Text('Sector Layout in a Widget Tree')
diff --git a/examples/layers/widgets/styled_text.dart b/examples/layers/widgets/styled_text.dart
index af6ce89..93ac0eb 100644
--- a/examples/layers/widgets/styled_text.dart
+++ b/examples/layers/widgets/styled_text.dart
@@ -118,8 +118,8 @@
 void main() {
   runApp(new MaterialApp(
     theme: new ThemeData.light(),
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) {
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) {
         return new Scaffold(
           toolBar: new ToolBar(
             center: new Text('Hal and Dave')),
diff --git a/examples/material_gallery/lib/gallery/app.dart b/examples/material_gallery/lib/gallery/app.dart
index 39fe069..642c0ba 100644
--- a/examples/material_gallery/lib/gallery/app.dart
+++ b/examples/material_gallery/lib/gallery/app.dart
@@ -28,7 +28,7 @@
       title: 'Flutter Material Gallery',
       theme: lightTheme ? new ThemeData.light() : new ThemeData.dark(),
       routes: {
-        '/': (RouteArguments args) => new GalleryHome()
+        '/': (BuildContext context) => new GalleryHome()
       }
     );
   }
diff --git a/examples/stocks/lib/main.dart b/examples/stocks/lib/main.dart
index d22b124..663f63f 100644
--- a/examples/stocks/lib/main.dart
+++ b/examples/stocks/lib/main.dart
@@ -114,9 +114,9 @@
       debugShowMaterialGrid: _configuration.debugShowGrid,
       showPerformanceOverlay: _configuration.showPerformanceOverlay,
       showSemanticsDebugger: _configuration.showSemanticsDebugger,
-      routes: <String, RouteBuilder>{
-         '/':         (RouteArguments args) => new StockHome(_stocks, _symbols, _configuration, configurationUpdater),
-         '/settings': (RouteArguments args) => new StockSettings(_configuration, configurationUpdater)
+      routes: <String, WidgetBuilder>{
+         '/':         (BuildContext context) => new StockHome(_stocks, _symbols, _configuration, configurationUpdater),
+         '/settings': (BuildContext context) => new StockSettings(_configuration, configurationUpdater)
       },
       onGenerateRoute: _getRoute,
       onLocaleChanged: _onLocaleChanged
diff --git a/packages/flutter/lib/src/material/app.dart b/packages/flutter/lib/src/material/app.dart
index 1d2a48c..c5894e2 100644
--- a/packages/flutter/lib/src/material/app.dart
+++ b/packages/flutter/lib/src/material/app.dart
@@ -28,7 +28,7 @@
     Key key,
     String title,
     ThemeData theme,
-    Map<String, RouteBuilder> routes: const <String, RouteBuilder>{},
+    Map<String, WidgetBuilder> routes: const <String, WidgetBuilder>{},
     RouteFactory onGenerateRoute,
     LocaleChangedCallback onLocaleChanged,
     this.debugShowMaterialGrid: false,
@@ -43,12 +43,10 @@
     color: theme?.primaryColor ?? Colors.blue[500], // blue[500] is the primary color of the default theme
     routes: routes,
     onGenerateRoute: (RouteSettings settings) {
-      RouteBuilder builder = routes[settings.name];
+      WidgetBuilder builder = routes[settings.name];
       if (builder != null) {
         return new MaterialPageRoute<Null>(
-          builder: (BuildContext context) {
-            return builder(new RouteArguments(context: context));
-          },
+          builder: builder,
           settings: settings
         );
       }
diff --git a/packages/flutter/lib/src/widgets/app.dart b/packages/flutter/lib/src/widgets/app.dart
index cfc719c..d1b91aa 100644
--- a/packages/flutter/lib/src/widgets/app.dart
+++ b/packages/flutter/lib/src/widgets/app.dart
@@ -28,12 +28,6 @@
 
 final AssetBundle _defaultBundle = _initDefaultBundle();
 
-class RouteArguments {
-  const RouteArguments({ this.context });
-  final BuildContext context;
-}
-typedef Widget RouteBuilder(RouteArguments args);
-
 typedef Future<LocaleQueryData> LocaleChangedCallback(Locale locale);
 
 class WidgetsApp extends StatefulWidget {
@@ -42,7 +36,7 @@
     this.title,
     this.textStyle,
     this.color,
-    this.routes: const <String, RouteBuilder>{},
+    this.routes: const <String, WidgetBuilder>{},
     this.onGenerateRoute,
     this.onLocaleChanged,
     this.showPerformanceOverlay: false,
@@ -72,7 +66,7 @@
   /// [Navigator] is given a named route, the name will be looked up
   /// in this table first. If the name is not available, then
   /// [onGenerateRoute] will be called instead.
-  final Map<String, RouteBuilder> routes;
+  final Map<String, WidgetBuilder> routes;
 
   /// The route generator callback used when the app is navigated to a
   /// named route but the name is not in the [routes] table.
diff --git a/packages/flutter/test/widget/bottom_sheet_rebuild_test.dart b/packages/flutter/test/widget/bottom_sheet_rebuild_test.dart
index 21ce1d8..568d528 100644
--- a/packages/flutter/test/widget/bottom_sheet_rebuild_test.dart
+++ b/packages/flutter/test/widget/bottom_sheet_rebuild_test.dart
@@ -14,8 +14,8 @@
       int buildCount = 0;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Scaffold(
               key: scaffoldKey,
               body: new Center(child: new Text('body'))
diff --git a/packages/flutter/test/widget/bottom_sheet_test.dart b/packages/flutter/test/widget/bottom_sheet_test.dart
index 1f04bf3..848f0c5 100644
--- a/packages/flutter/test/widget/bottom_sheet_test.dart
+++ b/packages/flutter/test/widget/bottom_sheet_test.dart
@@ -14,9 +14,9 @@
       bool showBottomSheetThenCalled = false;
 
       tester.pumpWidget(new MaterialApp(
-          routes: <String, RouteBuilder>{
-            '/': (RouteArguments args) {
-              context = args.context;
+          routes: <String, WidgetBuilder>{
+            '/': (BuildContext ctx) {
+              context = ctx;
               return new Container();
             }
           }
@@ -66,8 +66,8 @@
       bool showBottomSheetThenCalled = false;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Scaffold(
               key: scaffoldKey,
               body: new Center(child: new Text('body'))
diff --git a/packages/flutter/test/widget/draggable_test.dart b/packages/flutter/test/widget/draggable_test.dart
index cd417d6..b297c9a 100644
--- a/packages/flutter/test/widget/draggable_test.dart
+++ b/packages/flutter/test/widget/draggable_test.dart
@@ -12,8 +12,8 @@
       List<dynamic> accepted = <dynamic>[];
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) { return new Column(
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) { return new Column(
             children: <Widget>[
               new Draggable<int>(
                 data: 1,
@@ -75,8 +75,8 @@
       Point firstLocation, secondLocation;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) { return new Column(
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) { return new Column(
             children: <Widget>[
               new Draggable<int>(
                 data: 1,
@@ -173,8 +173,8 @@
       Point firstLocation, secondLocation;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) { return new Column(
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) { return new Column(
             children: <Widget>[
               new Draggable<int>(
                 data: 1,
@@ -234,8 +234,8 @@
       Point firstLocation, secondLocation;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) { return new Column(
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) { return new Column(
             children: <Widget>[
               new LongPressDraggable<int>(
                 data: 1,
@@ -285,8 +285,8 @@
       Point firstLocation, secondLocation;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) { return new Column(
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) { return new Column(
             children: <Widget>[
               new Draggable<int>(
                 data: 1,
@@ -337,8 +337,8 @@
       Point firstLocation, secondLocation, thirdLocation;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Block(
               children: <Widget>[
                 new DragTarget<int>(
@@ -448,8 +448,8 @@
       Point firstLocation, secondLocation, thirdLocation;
 
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Block(
               scrollDirection: Axis.horizontal,
               children: <Widget>[
diff --git a/packages/flutter/test/widget/drawer_test.dart b/packages/flutter/test/widget/drawer_test.dart
index 91e9a6f..3f8f5ad 100644
--- a/packages/flutter/test/widget/drawer_test.dart
+++ b/packages/flutter/test/widget/drawer_test.dart
@@ -15,9 +15,9 @@
       BuildContext context;
       tester.pumpWidget(
         new MaterialApp(
-          routes: <String, RouteBuilder>{
-            '/': (RouteArguments args) {
-              context = args.context;
+          routes: <String, WidgetBuilder>{
+            '/': (BuildContext ctx) {
+              context = ctx;
               return new Scaffold(
                 key: scaffoldKey,
                 drawer: new Text('drawer'),
@@ -48,8 +48,8 @@
       tester.pumpWidget(new Container()); // throw away the old App and its Navigator
       tester.pumpWidget(
         new MaterialApp(
-          routes: <String, RouteBuilder>{
-            '/': (RouteArguments args) {
+          routes: <String, WidgetBuilder>{
+            '/': (BuildContext context) {
               return new Scaffold(
                 key: scaffoldKey,
                 drawer: new Text('drawer'),
diff --git a/packages/flutter/test/widget/heroes_test.dart b/packages/flutter/test/widget/heroes_test.dart
index 3771893..646d8c6 100644
--- a/packages/flutter/test/widget/heroes_test.dart
+++ b/packages/flutter/test/widget/heroes_test.dart
@@ -12,21 +12,21 @@
 Key secondKey = new Key('second');
 Key thirdKey = new Key('third');
 
-final Map<String, RouteBuilder> routes = <String, RouteBuilder>{
-  '/': (RouteArguments args) => new Material(
+final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+  '/': (BuildContext context) => new Material(
     child: new Block(children: <Widget>[
       new Container(height: 100.0, width: 100.0),
       new Card(child: new Hero(tag: 'a', child: new Container(height: 100.0, width: 100.0, key: firstKey))),
       new Container(height: 100.0, width: 100.0),
-      new FlatButton(child: new Text('two'), onPressed: () => Navigator.pushNamed(args.context, '/two')),
+      new FlatButton(child: new Text('two'), onPressed: () => Navigator.pushNamed(context, '/two')),
     ])
   ),
-  '/two': (RouteArguments args) => new Material(
+  '/two': (BuildContext context) => new Material(
     child: new Block(children: <Widget>[
       new Container(height: 150.0, width: 150.0),
       new Card(child: new Hero(tag: 'a', child: new Container(height: 150.0, width: 150.0, key: secondKey))),
       new Container(height: 150.0, width: 150.0),
-      new FlatButton(child: new Text('three'), onPressed: () => Navigator.push(args.context, new ThreeRoute())),
+      new FlatButton(child: new Text('three'), onPressed: () => Navigator.push(context, new ThreeRoute())),
     ])
   ),
 };
diff --git a/packages/flutter/test/widget/modal_barrier_test.dart b/packages/flutter/test/widget/modal_barrier_test.dart
index de87cb4..c7b6d19 100644
--- a/packages/flutter/test/widget/modal_barrier_test.dart
+++ b/packages/flutter/test/widget/modal_barrier_test.dart
@@ -61,9 +61,9 @@
 
   test('ModalBarrier pops the Navigator when dismissed', () {
     testWidgets((WidgetTester tester) {
-      final Map<String, RouteBuilder> routes = <String, RouteBuilder>{
-        '/': (RouteArguments args) => new FirstWidget(),
-        '/modal': (RouteArguments args) => new SecondWidget(),
+      final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+        '/': (BuildContext context) => new FirstWidget(),
+        '/modal': (BuildContext context) => new SecondWidget(),
       };
 
       tester.pumpWidget(new MaterialApp(routes: routes));
diff --git a/packages/flutter/test/widget/navigator_test.dart b/packages/flutter/test/widget/navigator_test.dart
index 9dce4cb..221d4d9 100644
--- a/packages/flutter/test/widget/navigator_test.dart
+++ b/packages/flutter/test/widget/navigator_test.dart
@@ -66,9 +66,9 @@
 void main() {
   test('Can navigator navigate to and from a stateful widget', () {
     testWidgets((WidgetTester tester) {
-      final Map<String, RouteBuilder> routes = <String, RouteBuilder>{
-        '/': (RouteArguments args) => new FirstWidget(),
-        '/second': (RouteArguments args) => new SecondWidget(),
+      final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+        '/': (BuildContext context) => new FirstWidget(),
+        '/second': (BuildContext context) => new SecondWidget(),
       };
 
       tester.pumpWidget(new MaterialApp(routes: routes));
diff --git a/packages/flutter/test/widget/page_transitions_test.dart b/packages/flutter/test/widget/page_transitions_test.dart
index 8480dff..e3756c0 100644
--- a/packages/flutter/test/widget/page_transitions_test.dart
+++ b/packages/flutter/test/widget/page_transitions_test.dart
@@ -18,7 +18,7 @@
     testWidgets((WidgetTester tester) {
       GlobalKey containerKey1 = new GlobalKey();
       GlobalKey containerKey2 = new GlobalKey();
-      final Map<String, RouteBuilder> routes = <String, RouteBuilder>{
+      final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
         '/': (_) => new Container(key: containerKey1, child: new Text('Home')),
         '/settings': (_) => new Container(key: containerKey2, child: new Text('Settings')),
       };
diff --git a/packages/flutter/test/widget/snack_bar_test.dart b/packages/flutter/test/widget/snack_bar_test.dart
index eedafef..1152644 100644
--- a/packages/flutter/test/widget/snack_bar_test.dart
+++ b/packages/flutter/test/widget/snack_bar_test.dart
@@ -12,8 +12,8 @@
       String helloSnackBar = 'Hello SnackBar';
       Key tapTarget = new Key('tap-target');
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Scaffold(
               body: new Builder(
                 builder: (BuildContext context) {
@@ -63,8 +63,8 @@
       int snackBarCount = 0;
       Key tapTarget = new Key('tap-target');
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Scaffold(
               body: new Builder(
                 builder: (BuildContext context) {
@@ -146,8 +146,8 @@
       int time;
       ScaffoldFeatureController<SnackBar, Null> lastController;
       tester.pumpWidget(new MaterialApp(
-        routes: <String, RouteBuilder>{
-          '/': (RouteArguments args) {
+        routes: <String, WidgetBuilder>{
+          '/': (BuildContext context) {
             return new Scaffold(
               body: new Builder(
                 builder: (BuildContext context) {
diff --git a/packages/flutter/test/widget/two_level_list_test.dart b/packages/flutter/test/widget/two_level_list_test.dart
index 20fed40..4478290 100644
--- a/packages/flutter/test/widget/two_level_list_test.dart
+++ b/packages/flutter/test/widget/two_level_list_test.dart
@@ -13,7 +13,7 @@
     final Key sublistKey = new UniqueKey();
     final Key bottomKey = new UniqueKey();
 
-    final Map<String, RouteBuilder> routes = <String, RouteBuilder>{
+    final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (_) {
         return new Material(
           child: new Viewport(
diff --git a/packages/flutter_markdown/example/demo.dart b/packages/flutter_markdown/example/demo.dart
index 64eb2ac..f83b7f1 100644
--- a/packages/flutter_markdown/example/demo.dart
+++ b/packages/flutter_markdown/example/demo.dart
@@ -29,8 +29,8 @@
 void main() {
   runApp(new MaterialApp(
     title: "Markdown Demo",
-    routes: <String, RouteBuilder>{
-      '/': (RouteArguments args) => new Scaffold(
+    routes: <String, WidgetBuilder>{
+      '/': (BuildContext context) => new Scaffold(
         toolBar: new ToolBar(center: new Text("Markdown Demo")),
         body: new Markdown(data: _kMarkdownData)
       )
diff --git a/packages/flutter_tools/templates/create/lib/main.dart.tmpl b/packages/flutter_tools/templates/create/lib/main.dart.tmpl
index c996477..a5479f9 100644
--- a/packages/flutter_tools/templates/create/lib/main.dart.tmpl
+++ b/packages/flutter_tools/templates/create/lib/main.dart.tmpl
@@ -12,8 +12,8 @@
   runApp(
     new MaterialApp(
       title: 'Flutter Demo',
-      routes: <String, RouteBuilder>{
-        '/': (RouteArguments args) => new FlutterDemo()
+      routes: <String, WidgetBuilder>{
+        '/': (BuildContext context) => new FlutterDemo()
       }
     )
   );