Make the drawer, popup menus, dialogs, and settings page scrollable.

sky/sdk/lib/widgets/popup_menu.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'dart:async';
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 
 import '../animation/animated_value.dart';
 import '../painting/box_painter.dart';
 import '../theme/colors.dart';
 import '../theme/shadows.dart';
 import 'animated_component.dart';
 import 'basic.dart';
 import 'popup_menu_item.dart';
+import 'scrollable_viewport.dart';
 
 const double _kMenuOpenDuration = 300.0;
 const double _kMenuCloseDuration = 200.0;
 const double _kMenuCloseDelay = 100.0;
 const double _kMenuWidthStep = 56.0;
 const double _kMenuMargin = 16.0; // 24.0 on tablet
 const double _kMenuMinWidth = 2.0 * _kMenuWidthStep;
 const double _kMenuMaxWidth = 5.0 * _kMenuWidthStep;
 const double _kMenuHorizontalPadding = 16.0;
 const double _kMenuVerticalPadding = 8.0;
@@ skipping 89 matching lines @@
               minWidth: _kMenuMinWidth,
               maxWidth: _kMenuMaxWidth
             ),
             child: new ShrinkWrapWidth(
               stepWidth: _kMenuWidthStep,
               child: new Container(
                 padding: const EdgeDims.symmetric(
                   horizontal: _kMenuHorizontalPadding,
                   vertical: _kMenuVerticalPadding
                 ),
-                child: new Block(children)
+                child: new ScrollableViewport(
+                  child: new Block(children)
+                )
               )
             )
           )
         )
       )
     );
   }
 
 }