[Effen] fix some dart warnings (mostly unused imports)

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1104233003

framework/animation/animated_value.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import '../fn.dart';
 import 'curves.dart';
 import 'dart:async';
 import 'generators.dart';

framework/components/animated_component.dart

@@ -6,7 +6,7 @@ import '../animation/animated_value.dart';
 import '../fn.dart';
 import 'dart:mirrors';
 
-class AnimatedComponent extends Component {
+abstract class AnimatedComponent extends Component {
   AnimatedComponent({ Object key }) : super(key: key, stateful: true);
 
   animateField(AnimatedValue value, Symbol symbol) {

framework/components/drawer.dart

@@ -7,8 +7,6 @@ import '../animation/animated_value.dart';
 import '../animation/curves.dart';
 import '../fn.dart';
 import '../theme/colors.dart';
-import '../theme/shadows.dart';
-import 'dart:async';
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'material.dart';

framework/components/fixed_height_scrollable.dart

@@ -9,7 +9,6 @@ import 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'dart:async';
 import 'scrollable.dart';
-import '../layouts/block.dart';
 
 abstract class FixedHeightScrollable extends Scrollable {
   static final Style _style = new Style('''
@@ -28,6 +27,7 @@ abstract class FixedHeightScrollable extends Scrollable {
   }) : super(key: key);
 
   ScrollBehavior createScrollBehavior() => new OverscrollBehavior();
+  OverscrollBehavior get scrollBehavior => super.scrollBehavior as OverscrollBehavior;
 
   double _height = 0.0;
   double _itemHeight;
@@ -106,4 +106,6 @@ abstract class FixedHeightScrollable extends Scrollable {
       ]
     );
   }
+
+  List<UINode> buildItems(int start, int count);  
 }

framework/components/ink_splash.dart

@@ -4,7 +4,6 @@
 
 import '../animation/animated_value.dart';
 import '../animation/curves.dart';
-import '../animation/generators.dart';
 import '../fn.dart';
 import '../theme/view-configuration.dart' as config;
 import 'dart:async';

framework/components/material.dart

@@ -4,7 +4,6 @@
 
 import '../fn.dart';
 import '../theme/shadows.dart';
-import 'ink_well.dart';
 
 class Material extends Component {
   static final List<Style> _shadowStyle = [

framework/components/popup_menu.dart

@@ -6,10 +6,8 @@ import 'animated_component.dart';
 import '../animation/animated_value.dart';
 import '../fn.dart';
 import '../theme/colors.dart';
-import '../theme/view-configuration.dart';
 import 'dart:async';
 import 'dart:math' as math;
-import 'dart:sky' as sky;
 import 'material.dart';
 import 'popup_menu_item.dart';
 
@@ -44,7 +42,7 @@ class PopupMenuController {
       _state = MenuState.Hidden;
       _closeState = null;
       result.complete();
-      return;
+      return result.future;
     }
     assert(_closeState != null);
     return _closeState;

framework/components/popup_menu_item.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'animated_component.dart';
-import '../animation/animated_value.dart';
 import '../fn.dart';
 import 'ink_well.dart';
 

framework/components/scaffold.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import '../fn.dart';
-import 'action_bar.dart';
 import 'drawer.dart';
 import 'floating_action_button.dart';
 import 'package:sky/framework/theme/typography.dart' as typography;