fix lints for directives_ordering rule (#8382)

dev/benchmarks/microbenchmarks/lib/gestures/velocity_tracker_bench.dart

@@ -3,9 +3,9 @@
 // found in the LICENSE file.
 
 import 'package:flutter/gestures.dart';
-import 'data/velocity_tracker_data.dart';
 
 import '../common.dart';
+import 'data/velocity_tracker_data.dart';
 
 const int _kNumIters = 10000;
 

dev/bots/test.dart

-import 'dart:io';
 import 'dart:async';
+import 'dart:io';
 
 import 'package:path/path.dart' as p;
 

dev/devicelab/lib/tasks/size_tests.dart

@@ -4,11 +4,11 @@
 
 import 'dart:io';
 
+import 'package:flutter_devicelab/framework/adb.dart';
+
 import '../framework/framework.dart';
 import '../framework/utils.dart';
 
-import 'package:flutter_devicelab/framework/adb.dart';
-
 TaskFunction createBasicMaterialAppSizeTest() {
   return () async {
     const String sampleAppName = 'sample_flutter_app';

examples/flutter_gallery/lib/demo/all.dart

@@ -4,11 +4,11 @@
 
 export 'bottom_navigation_demo.dart';
 export 'buttons_demo.dart';
-export 'contacts_demo.dart';
-export 'cards_demo.dart';
 export 'calculator_demo.dart';
+export 'cards_demo.dart';
 export 'chip_demo.dart';
 export 'colors_demo.dart';
+export 'contacts_demo.dart';
 export 'data_table_demo.dart';
 export 'date_and_time_picker_demo.dart';
 export 'dialog_demo.dart';
@@ -22,8 +22,8 @@ export 'menu_demo.dart';
 export 'modal_bottom_sheet_demo.dart';
 export 'overscroll_demo.dart';
 export 'page_selector_demo.dart';
-export 'pesto_demo.dart';
 export 'persistent_bottom_sheet_demo.dart';
+export 'pesto_demo.dart';
 export 'progress_indicator_demo.dart';
 export 'scrollable_tabs_demo.dart';
 export 'selection_controls_demo.dart';

examples/flutter_gallery/lib/gallery/app.dart

@@ -8,8 +8,8 @@ import 'package:flutter/foundation.dart' show defaultTargetPlatform;
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart' show timeDilation;
 
-import 'item.dart';
 import 'home.dart';
+import 'item.dart';
 import 'updates.dart';
 
 final Map<String, WidgetBuilder> _kRoutes = new Map<String, WidgetBuilder>.fromIterable(

examples/layers/raw/canvas.dart

@@ -5,9 +5,9 @@
 // This example shows how to use the ui.Canvas interface to draw various shapes
 // with gradients and transforms.
 
-import 'dart:ui' as ui;
 import 'dart:math' as math;
 import 'dart:typed_data';
+import 'dart:ui' as ui;
 
 ui.Picture paint(ui.Rect paintBounds) {
   // First we create a PictureRecorder to record the commands we're going to

examples/layers/raw/text.dart

@@ -5,8 +5,8 @@
 // This example shows how to draw some bi-directional text using the raw
 // interface to the engine.
 
-import 'dart:ui' as ui;
 import 'dart:typed_data';
+import 'dart:ui' as ui;
 
 // A paragraph represents a rectangular region that contains some text.
 ui.Paragraph paragraph;

examples/layers/raw/touch_input.dart

@@ -5,8 +5,8 @@
 // This example shows how to put some pixels on the screen using the raw
 // interface to the engine.
 
-import 'dart:ui' as ui;
 import 'dart:typed_data';
+import 'dart:ui' as ui;
 
 ui.Color color;
 

examples/layers/test/sector_test.dart

@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import '../rendering/src/sector_layout.dart';
 import 'package:test/test.dart';
 
+import '../rendering/src/sector_layout.dart';
+
 void main() {
   test('SectorConstraints', () {
     expect(const SectorConstraints().isTight, isFalse);

examples/stocks/lib/stock_row.dart

@@ -4,8 +4,8 @@
 
 import 'package:flutter/material.dart';
 
-import 'stock_data.dart';
 import 'stock_arrow.dart';
+import 'stock_data.dart';
 
 typedef void StockRowActionCallback(Stock stock);
 

examples/stocks/lib/stock_symbol_viewer.dart

@@ -4,8 +4,8 @@
 
 import 'package:flutter/material.dart';
 
-import 'stock_data.dart';
 import 'stock_arrow.dart';
+import 'stock_data.dart';
 
 class _StockSymbolView extends StatelessWidget {
   _StockSymbolView({ this.stock, this.arrow });

packages/flutter/lib/foundation.dart

@@ -9,6 +9,12 @@
 /// framework.
 library foundation;
 
+export 'package:meta/meta.dart' show
+  mustCallSuper,
+  optionalTypeArgs,
+  protected,
+  required;
+
 export 'src/foundation/assertions.dart';
 export 'src/foundation/basic_types.dart';
 export 'src/foundation/binding.dart';
@@ -19,9 +25,3 @@ export 'src/foundation/observer_list.dart';
 export 'src/foundation/platform.dart';
 export 'src/foundation/print.dart';
 export 'src/foundation/synchronous_future.dart';
-
-export 'package:meta/meta.dart' show
-  mustCallSuper,
-  optionalTypeArgs,
-  protected,
-  required;

packages/flutter/lib/http.dart

@@ -16,5 +16,5 @@
 library http;
 
 export 'src/http/http.dart';
-export 'src/http/response.dart';
 export 'src/http/mock_client.dart';
+export 'src/http/response.dart';

packages/flutter/lib/material.dart

@@ -70,8 +70,8 @@ export 'src/material/slider.dart';
 export 'src/material/snack_bar.dart';
 export 'src/material/stepper.dart';
 export 'src/material/switch.dart';
-export 'src/material/tabs.dart';
 export 'src/material/tab_controller.dart';
+export 'src/material/tabs.dart';
 export 'src/material/theme.dart';
 export 'src/material/theme_data.dart';
 export 'src/material/time_picker.dart';
@@ -80,5 +80,4 @@ export 'src/material/tooltip.dart';
 export 'src/material/two_level_list.dart';
 export 'src/material/typography.dart';
 export 'src/material/user_accounts_drawer_header.dart';
-
 export 'widgets.dart';

packages/flutter/lib/painting.dart

@@ -21,10 +21,10 @@ export 'src/painting/basic_types.dart';
 export 'src/painting/box_painter.dart';
 export 'src/painting/colors.dart';
 export 'src/painting/decoration.dart';
-export 'src/painting/image_fit.dart';
 export 'src/painting/edge_insets.dart';
-export 'src/painting/fractional_offset.dart';
 export 'src/painting/flutter_logo.dart';
+export 'src/painting/fractional_offset.dart';
+export 'src/painting/image_fit.dart';
 export 'src/painting/text_editing.dart';
 export 'src/painting/text_painter.dart';
 export 'src/painting/text_span.dart';

packages/flutter/lib/physics.dart

@@ -11,8 +11,8 @@ library physics;
 export 'src/physics/clamped_simulation.dart';
 export 'src/physics/friction_simulation.dart';
 export 'src/physics/gravity_simulation.dart';
-export 'src/physics/simulation_group.dart';
 export 'src/physics/simulation.dart';
+export 'src/physics/simulation_group.dart';
 export 'src/physics/spring_simulation.dart';
 export 'src/physics/tolerance.dart';
 export 'src/physics/utils.dart';

packages/flutter/lib/rendering.dart

@@ -22,6 +22,13 @@
 /// initialized with those features.
 library rendering;
 
+export 'package:flutter/foundation.dart' show
+  VoidCallback,
+  ValueChanged,
+  ValueGetter,
+  ValueSetter;
+export 'package:vector_math/vector_math_64.dart' show Matrix4;
+
 export 'src/rendering/animated_size.dart';
 export 'src/rendering/binding.dart';
 export 'src/rendering/block.dart';
@@ -53,13 +60,5 @@ export 'src/rendering/stack.dart';
 export 'src/rendering/table.dart';
 export 'src/rendering/tweens.dart';
 export 'src/rendering/view.dart';
-export 'src/rendering/viewport_offset.dart';
 export 'src/rendering/viewport.dart';
-
-export 'package:flutter/foundation.dart' show
-  VoidCallback,
-  ValueChanged,
-  ValueGetter,
-  ValueSetter;
-
-export 'package:vector_math/vector_math_64.dart' show Matrix4;
+export 'src/rendering/viewport_offset.dart';

packages/flutter/lib/src/foundation/debug.dart

@@ -3,8 +3,8 @@
 // found in the LICENSE file.
 
 import 'assertions.dart';
-import 'print.dart';
 import 'platform.dart';
+import 'print.dart';
 
 /// Returns true if none of the foundation library debug variables have been
 /// changed.

packages/flutter/lib/src/gestures/drag.dart

@@ -5,9 +5,9 @@
 import 'package:flutter/foundation.dart';
 
 import 'arena.dart';
-import 'recognizer.dart';
 import 'constants.dart';
 import 'events.dart';
+import 'recognizer.dart';
 import 'velocity_tracker.dart';
 
 enum _DragState {

packages/flutter/lib/src/gestures/scale.dart

@@ -3,9 +3,9 @@
 // found in the LICENSE file.
 
 import 'arena.dart';
-import 'recognizer.dart';
 import 'constants.dart';
 import 'events.dart';
+import 'recognizer.dart';
 import 'velocity_tracker.dart';
 
 /// The possible states of a [ScaleGestureRecognizer].

packages/flutter/lib/src/material/bottom_navigation_bar.dart

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:math' as math;
 import 'dart:collection' show Queue;
+import 'dart:math' as math;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';

packages/flutter/lib/src/material/button.dart

@@ -9,8 +9,8 @@ import 'colors.dart';
 import 'constants.dart';
 import 'debug.dart';
 import 'flat_button.dart';
-import 'icon_theme_data.dart';
 import 'icon_theme.dart';
+import 'icon_theme_data.dart';
 import 'ink_well.dart';
 import 'material.dart';
 import 'raised_button.dart';

packages/flutter/lib/src/material/date_picker.dart

@@ -12,14 +12,14 @@ import 'package:flutter/widgets.dart';
 import 'package:intl/date_symbols.dart';
 import 'package:intl/intl.dart';
 
-import 'button_bar.dart';
 import 'button.dart';
+import 'button_bar.dart';
 import 'colors.dart';
 import 'debug.dart';
 import 'dialog.dart';
 import 'flat_button.dart';
-import 'icon_button.dart';
 import 'icon.dart';
+import 'icon_button.dart';
 import 'icons.dart';
 import 'ink_well.dart';
 import 'theme.dart';

packages/flutter/lib/src/material/dropdown.dart

@@ -13,10 +13,10 @@ import 'debug.dart';
 import 'icon.dart';
 import 'icons.dart';
 import 'ink_well.dart';
+import 'material.dart';
 import 'scrollbar.dart';
 import 'shadows.dart';
 import 'theme.dart';
-import 'material.dart';
 
 const Duration _kDropdownMenuDuration = const Duration(milliseconds: 300);
 const double _kMenuItemHeight = 48.0;

packages/flutter/lib/src/material/expand_icon.dart

@@ -8,8 +8,8 @@ import 'package:flutter/widgets.dart';
 import 'colors.dart';
 import 'debug.dart';
 import 'icon.dart';
-import 'icons.dart';
 import 'icon_button.dart';
+import 'icons.dart';
 import 'theme.dart';
 
 /// A widget representing a rotating expand/collapse button. The icon rotates

packages/flutter/lib/src/material/floating_action_button.dart

@@ -6,8 +6,8 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';
-import 'icon_theme_data.dart';
 import 'icon_theme.dart';
+import 'icon_theme_data.dart';
 import 'ink_well.dart';
 import 'material.dart';
 import 'theme.dart';

packages/flutter/lib/src/material/flutter_logo.dart

@@ -4,9 +4,9 @@
 
 import 'package:flutter/widgets.dart';
 
+import 'colors.dart';
 import 'icon_theme.dart';
 import 'icon_theme_data.dart';
-import 'colors.dart';
 
 /// The Flutter logo, in widget form. This widget respects the [IconTheme].
 ///

packages/flutter/lib/src/material/icon.dart

@@ -4,10 +4,10 @@
 
 import 'package:flutter/widgets.dart';
 
-import 'icons.dart';
 import 'icon_button.dart';
 import 'icon_theme.dart';
 import 'icon_theme_data.dart';
+import 'icons.dart';
 import 'theme.dart';
 
 /// A material design icon.

packages/flutter/lib/src/material/icon_theme.dart

@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'icon_theme_data.dart';
-import 'package:flutter/foundation.dart';
 import 'theme.dart';
 
 /// Controls the default color, opacity, and size of icons in a widget subtree.

packages/flutter/lib/src/material/icon_theme_data.dart

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui show lerpDouble;
 import 'dart:ui' show Color, hashValues;
+import 'dart:ui' as ui show lerpDouble;
 
 /// Defines the color, opacity, and size of icons.
 ///

packages/flutter/lib/src/material/image_icon.dart

@@ -5,10 +5,10 @@
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 
-import 'icons.dart';
 import 'icon_button.dart';
 import 'icon_theme.dart';
 import 'icon_theme_data.dart';
+import 'icons.dart';
 
 /// An icon that comes from an [ImageProvider], e.g. an [AssetImage].
 ///

packages/flutter/lib/src/material/mergeable_material.dart

@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ui' show lerpDouble;
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 
-import 'dart:ui' show lerpDouble;
-
 /// The base type for [MaterialSlice] and [MaterialGap].
 ///
 /// All [MergeableMaterialItem] objects need a [LocalKey].

packages/flutter/lib/src/material/popup_menu.dart

@@ -10,10 +10,10 @@ import 'package:flutter/widgets.dart';
 import 'constants.dart';
 import 'divider.dart';
 import 'icon.dart';
-import 'icons.dart';
 import 'icon_button.dart';
 import 'icon_theme.dart';
 import 'icon_theme_data.dart';
+import 'icons.dart';
 import 'ink_well.dart';
 import 'list_item.dart';
 import 'material.dart';

packages/flutter/lib/src/material/refresh_indicator.dart

@@ -7,8 +7,8 @@ import 'dart:math' as math;
 
 import 'package:flutter/widgets.dart';
 
-import 'theme.dart';
 import 'progress_indicator.dart';
+import 'theme.dart';
 
 // The over-scroll distance that moves the indicator to its maximum
 // displacement, as a percentage of the scrollable's container extent.

packages/flutter/lib/src/material/snack_bar.dart

@@ -9,8 +9,8 @@ import 'button.dart';
 import 'flat_button.dart';
 import 'material.dart';
 import 'scaffold.dart';
-import 'theme_data.dart';
 import 'theme.dart';
+import 'theme_data.dart';
 
 // https://material.google.com/components/snackbars-toasts.html#snackbars-toasts-specs
 const double _kSnackBarPadding = 24.0;

packages/flutter/lib/src/material/time_picker.dart

@@ -9,8 +9,8 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 
-import 'button_bar.dart';
 import 'button.dart';
+import 'button_bar.dart';
 import 'colors.dart';
 import 'dialog.dart';
 import 'flat_button.dart';

packages/flutter/lib/src/material/two_level_list.dart

@@ -7,9 +7,9 @@ import 'package:flutter/widgets.dart';
 
 import 'colors.dart';
 import 'icon.dart';
-import 'icons.dart';
 import 'icon_theme.dart';
 import 'icon_theme_data.dart';
+import 'icons.dart';
 import 'list_item.dart';
 import 'theme.dart';
 import 'theme_data.dart';

packages/flutter/lib/src/painting/flutter_logo.dart

@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui show Gradient, TextBox, lerpDouble;
 import 'dart:math' as math;
 import 'dart:typed_data';
+import 'dart:ui' as ui show Gradient, TextBox, lerpDouble;
 
 import 'package:flutter/services.dart';
 

packages/flutter/lib/src/painting/fractional_offset.dart

@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'basic_types.dart';
 import 'dart:ui' as ui show lerpDouble;
 
+import 'basic_types.dart';
+
 /// An offset that's expressed as a fraction of a Size.
 ///
 /// FractionalOffset(1.0, 0.0) represents the top right of the Size,

packages/flutter/lib/src/painting/text_editing.dart

@@ -4,10 +4,10 @@
 
 import 'dart:ui' show hashValues, TextAffinity, TextPosition;
 
-export 'dart:ui' show TextAffinity, TextPosition;
-
 import 'package:meta/meta.dart';
 
+export 'dart:ui' show TextAffinity, TextPosition;
+
 /// A range of characters in a string of text.
 class TextRange {
   /// Creates a text range.

packages/flutter/lib/src/rendering/binding.dart

@@ -14,8 +14,8 @@ import 'package:flutter/services.dart';
 import 'box.dart';
 import 'debug.dart';
 import 'object.dart';
-import 'view.dart';
 import 'semantics.dart';
+import 'view.dart';
 
 export 'package:flutter/gestures.dart' show HitTestResult;
 

packages/flutter/lib/src/rendering/object.dart

@@ -9,14 +9,13 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/painting.dart';
 import 'package:flutter/scheduler.dart';
-
 import 'package:vector_math/vector_math_64.dart';
 
+import 'binding.dart';
 import 'debug.dart';
 import 'layer.dart';
 import 'node.dart';
 import 'semantics.dart';
-import 'binding.dart';
 
 export 'package:flutter/foundation.dart' show FlutterError, InformationCollector;
 export 'package:flutter/gestures.dart' show HitTestEntry, HitTestResult;

packages/flutter/lib/src/rendering/performance_overlay.dart

@@ -3,8 +3,8 @@
 // found in the LICENSE file.
 
 import 'box.dart';
-import 'object.dart';
 import 'layer.dart';
+import 'object.dart';
 
 /// The options that control whether the performance overlay displays certain
 /// aspects of the compositor.

packages/flutter/lib/src/rendering/semantics.dart

@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:typed_data';
 import 'dart:ui' as ui;
 import 'dart:ui' show Rect, SemanticsAction, SemanticsFlags;
-import 'dart:typed_data';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';

packages/flutter/lib/src/rendering/sliver.dart

@@ -9,8 +9,8 @@ import 'package:flutter/gestures.dart';
 import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
 
-import 'box.dart';
 import 'binding.dart';
+import 'box.dart';
 import 'debug.dart';
 import 'object.dart';
 import 'viewport_offset.dart';

packages/flutter/lib/src/rendering/sliver_multi_box_adaptor.dart

@@ -7,8 +7,8 @@ import 'package:flutter/gestures.dart';
 import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
 
-import 'box.dart';
 import 'binding.dart';
+import 'box.dart';
 import 'object.dart';
 import 'sliver.dart';
 

packages/flutter/lib/src/rendering/sliver_persistent_header.dart

@@ -9,8 +9,8 @@ import 'package:flutter/gestures.dart';
 import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
 
-import 'box.dart';
 import 'binding.dart';
+import 'box.dart';
 import 'object.dart';
 import 'sliver.dart';
 import 'viewport_offset.dart';

packages/flutter/lib/src/rendering/view.dart

@@ -8,11 +8,11 @@ import 'dart:ui' as ui show Scene, SceneBuilder, window;
 
 import 'package:vector_math/vector_math_64.dart';
 
+import 'binding.dart';
 import 'box.dart';
 import 'debug.dart';
 import 'layer.dart';
 import 'object.dart';
-import 'binding.dart';
 
 /// The layout constraints for the root render object.
 class ViewConfiguration {

packages/flutter/lib/src/rendering/viewport.dart

@@ -9,8 +9,8 @@ import 'package:flutter/gestures.dart';
 import 'package:meta/meta.dart';
 import 'package:vector_math/vector_math_64.dart';
 
-import 'box.dart';
 import 'binding.dart';
+import 'box.dart';
 import 'object.dart';
 import 'sliver.dart';
 import 'viewport_offset.dart';

packages/flutter/lib/src/services/image_provider.dart

@@ -4,9 +4,9 @@
 
 import 'dart:async';
 import 'dart:io' show File;
-import 'dart:ui' show Size, Locale, hashValues;
-import 'dart:ui' as ui show Image;
 import 'dart:typed_data';
+import 'dart:ui' as ui show Image;
+import 'dart:ui' show Size, Locale, hashValues;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/http.dart' as http;

packages/flutter/lib/src/widgets/basic.dart

@@ -11,8 +11,8 @@ import 'package:flutter/services.dart';
 import 'debug.dart';
 import 'framework.dart';
 
-export 'package:flutter/foundation.dart' show TargetPlatform;
 export 'package:flutter/animation.dart';
+export 'package:flutter/foundation.dart' show TargetPlatform;
 export 'package:flutter/painting.dart';
 export 'package:flutter/rendering.dart' show
   Axis,

packages/flutter/lib/src/widgets/binding.dart

@@ -4,8 +4,8 @@
 
 import 'dart:async';
 import 'dart:developer' as developer;
-import 'dart:ui' as ui show window;
 import 'dart:ui' show AppLifecycleState, Locale;
+import 'dart:ui' as ui show window;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';

packages/flutter/lib/src/widgets/framework.dart

@@ -6,12 +6,13 @@ import 'dart:async';
 import 'dart:collection';
 import 'dart:developer';
 
-import 'debug.dart';
-
-import 'package:flutter/rendering.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/rendering.dart';
+
+import 'debug.dart';
 
 export 'dart:ui' show hashValues, hashList;
+
 export 'package:flutter/foundation.dart' show FlutterError, debugPrint, debugPrintStack;
 export 'package:flutter/foundation.dart' show VoidCallback, ValueChanged, ValueGetter, ValueSetter;
 export 'package:flutter/rendering.dart' show RenderObject, RenderBox, debugDumpRenderTree;

packages/flutter/lib/src/widgets/layout_builder.dart

@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'debug.dart';
-import 'framework.dart';
-
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 
+import 'debug.dart';
+import 'framework.dart';
+
 /// The signature of the [LayoutBuilder] builder function.
 typedef Widget LayoutWidgetBuilder(BuildContext context, BoxConstraints constraints);
 

packages/flutter/lib/src/widgets/scroll_configuration.dart

@@ -6,8 +6,8 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 
 import 'framework.dart';
-import 'scroll_physics.dart';
 import 'overscroll_indicator.dart';
+import 'scroll_physics.dart';
 
 class ScrollBehavior {
   const ScrollBehavior();

packages/flutter/lib/src/widgets/scroll_notification.dart

@@ -6,8 +6,8 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 
-import 'framework.dart';
 import 'basic.dart';
+import 'framework.dart';
 import 'notification_listener.dart';
 import 'scrollable.dart' show Scrollable, ScrollableState;
 

packages/flutter/lib/src/widgets/scroll_physics.dart

@@ -7,8 +7,8 @@ import 'dart:math' as math;
 import 'package:flutter/physics.dart';
 
 import 'overscroll_indicator.dart';
-import 'scroll_simulation.dart';
 import 'scroll_position.dart';
+import 'scroll_simulation.dart';
 
 // The ScrollPhysics base class is defined in scroll_position.dart because it
 // has as circular dependency with ScrollPosition.

packages/flutter/lib/src/widgets/sliver.dart

@@ -7,8 +7,8 @@ import 'dart:collection' show SplayTreeMap, HashMap;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 
-import 'framework.dart';
 import 'basic.dart';
+import 'framework.dart';
 
 export 'package:flutter/rendering.dart' show
   SliverGridDelegate,

packages/flutter/lib/widgets.dart

@@ -7,6 +7,8 @@
 /// To use, import `package:flutter/widgets.dart`.
 library widgets;
 
+export 'package:vector_math/vector_math_64.dart' show Matrix4;
+
 export 'src/widgets/animated_cross_fade.dart';
 export 'src/widgets/animated_size.dart';
 export 'src/widgets/app.dart';
@@ -67,5 +69,3 @@ export 'src/widgets/transitions.dart';
 export 'src/widgets/unique_widget.dart';
 export 'src/widgets/viewport.dart';
 export 'src/widgets/will_pop_scope.dart';
-
-export 'package:vector_math/vector_math_64.dart' show Matrix4;

packages/flutter/test/examples/sector_layout_test.dart

@@ -4,8 +4,8 @@
 
 import 'package:test/test.dart';
 
-import '../rendering/rendering_tester.dart';
 import '../../../../examples/layers/rendering/custom_coordinate_systems.dart';
+import '../rendering/rendering_tester.dart';
 
 void main() {
   test('Sector layout can paint', () {

packages/flutter/test/rendering/debug_test.dart

@@ -6,8 +6,8 @@ import 'package:flutter/rendering.dart';
 import 'package:test/test.dart';
 import 'package:vector_math/vector_math_64.dart';
 
-import 'rendering_tester.dart';
 import 'mock_canvas.dart';
+import 'rendering_tester.dart';
 
 void main() {
   test('Describe transform control test', () {

packages/flutter/test/services/image_decoder_test.dart

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui' as ui;
 import 'dart:typed_data';
+import 'dart:ui' as ui;
 
 import 'package:flutter/services.dart';
 import 'package:test/test.dart';

packages/flutter/test/widgets/async_test.dart

@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter_test/flutter_test.dart';
-import 'package:flutter/widgets.dart';
 import 'dart:async';
 
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
 void main() {
-  Widget snapshotText(BuildContext context, AsyncSnapshot<String> snapshot) { 
+  Widget snapshotText(BuildContext context, AsyncSnapshot<String> snapshot) {
     return new Text(snapshot.toString());
   }
   group('Async smoke tests', () {

packages/flutter_driver/lib/flutter_driver.dart

@@ -13,35 +13,28 @@ library flutter_driver;
 
 export 'src/common.dart' show
   testOutputsDirectory;
-
 export 'src/driver.dart' show
   find,
   CommonFinders,
   EvaluatorFunction,
   FlutterDriver,
   TimelineStream;
-
 export 'src/error.dart' show
   DriverError,
   LogLevel,
   LogRecord,
   flutterDriverLog;
-
 export 'src/find.dart' show
   SerializableFinder,
   GetTextResult;
-
 export 'src/health.dart' show
   Health,
   HealthStatus;
-
 export 'src/message.dart' show
   Command,
   Result;
-
-export 'src/timeline_summary.dart' show
-  TimelineSummary;
-
 export 'src/timeline.dart' show
   Timeline,
   TimelineEvent;
+export 'src/timeline_summary.dart' show
+  TimelineSummary;

packages/flutter_driver/lib/src/driver.dart

@@ -4,8 +4,9 @@
 
 import 'dart:async';
 import 'dart:convert';
-import 'package:file/file.dart' as f;
 import 'dart:io';
+
+import 'package:file/file.dart' as f;
 import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as p;

packages/flutter_driver/lib/src/extension.dart

@@ -13,12 +13,12 @@ import 'package:flutter_test/flutter_test.dart';
 
 import 'error.dart';
 import 'find.dart';
+import 'frame_sync.dart';
 import 'gesture.dart';
 import 'health.dart';
 import 'input.dart';
 import 'message.dart';
 import 'render_tree.dart';
-import 'frame_sync.dart';
 
 const String _extensionMethodName = 'driver';
 const String _extensionMethod = 'ext.flutter.$_extensionMethodName';

packages/flutter_driver/lib/src/gesture.dart

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'message.dart';
 import 'find.dart';
+import 'message.dart';
 
 /// Taps on a target widget located by [finder].
 class Tap extends CommandWithTarget {

packages/flutter_driver/lib/src/input.dart

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'message.dart';
 import 'find.dart';
+import 'message.dart';
 
 /// Sets [text] in a text input widget.
 class SetInputText extends CommandWithTarget {

packages/flutter_driver/test/all.dart

@@ -4,8 +4,8 @@
 
 import 'flutter_driver_test.dart' as flutter_driver_test;
 import 'src/retry_test.dart' as retry_test;
-import 'src/timeline_test.dart' as timeline_test;
 import 'src/timeline_summary_test.dart' as timeline_summary_test;
+import 'src/timeline_test.dart' as timeline_test;
 
 void main() {
   flutter_driver_test.main();

packages/flutter_test/lib/flutter_test.dart

@@ -12,8 +12,8 @@ export 'src/binding.dart';
 export 'src/controller.dart';
 export 'src/finders.dart';
 export 'src/matchers.dart';
-export 'src/test_async_utils.dart';
 export 'src/stack_manipulation.dart';
+export 'src/test_async_utils.dart';
 export 'src/test_pointer.dart';
 export 'src/test_text_input.dart';
 export 'src/test_vsync.dart';

packages/flutter_test/lib/src/finders.dart

@@ -3,11 +3,10 @@
 // found in the LICENSE file.
 
 import 'package:flutter/material.dart';
+import 'package:meta/meta.dart';
 
 import 'all_elements.dart';
 
-import 'package:meta/meta.dart';
-
 /// Signature for [CommonFinders.byPredicate].
 typedef bool WidgetPredicate(Widget widget);
 

packages/flutter_tools/lib/executable.dart

@@ -5,10 +5,11 @@
 import 'dart:async';
 
 import 'package:args/command_runner.dart';
+import 'package:intl/intl_standalone.dart' as intl;
 import 'package:process/process.dart';
 import 'package:stack_trace/stack_trace.dart';
-import 'package:intl/intl_standalone.dart' as intl;
 
+import 'src/artifacts.dart';
 import 'src/base/common.dart';
 import 'src/base/config.dart';
 import 'src/base/context.dart';
@@ -41,7 +42,6 @@ import 'src/commands/test.dart';
 import 'src/commands/trace.dart';
 import 'src/commands/update_packages.dart';
 import 'src/commands/upgrade.dart';
-import 'src/artifacts.dart';
 import 'src/devfs.dart';
 import 'src/device.dart';
 import 'src/doctor.dart';

packages/flutter_tools/lib/src/android/android_studio_validator.dart

@@ -6,11 +6,11 @@ import 'dart:async';
 
 import '../base/file_system.dart';
 import '../base/io.dart';
-import '../doctor.dart';
-import '../globals.dart';
 import '../base/platform.dart';
 import '../base/process_manager.dart';
 import '../base/version.dart';
+import '../doctor.dart';
+import '../globals.dart';
 import 'android_studio.dart';
 
 class AndroidStudioValidator extends DoctorValidator {

packages/flutter_tools/lib/src/android/gradle.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import '../artifacts.dart';
 import '../base/common.dart';
 import '../base/file_system.dart';
 import '../base/logger.dart';
@@ -11,7 +12,6 @@ import '../base/os.dart';
 import '../base/platform.dart';
 import '../base/process.dart';
 import '../base/utils.dart';
-import '../artifacts.dart';
 import '../build_info.dart';
 import '../cache.dart';
 import '../globals.dart';

packages/flutter_tools/lib/src/asset.dart

@@ -11,8 +11,8 @@ import 'package:yaml/yaml.dart';
 import 'base/file_system.dart';
 import 'build_info.dart';
 import 'cache.dart';
-import 'devfs.dart';
 import 'dart/package_map.dart';
+import 'devfs.dart';
 import 'globals.dart';
 
 /// A bundle of assets.

packages/flutter_tools/lib/src/base/process.dart

@@ -5,10 +5,10 @@
 import 'dart:async';
 import 'dart:convert';
 
+import '../globals.dart';
 import 'file_system.dart';
 import 'io.dart';
 import 'process_manager.dart';
-import '../globals.dart';
 
 typedef String StringConverter(String string);
 typedef Future<dynamic> ShutdownHook();

packages/flutter_tools/lib/src/commands/build.dart

@@ -12,8 +12,8 @@ import '../base/utils.dart';
 import '../build_info.dart';
 import '../globals.dart';
 import '../runner/flutter_command.dart';
-import 'build_apk.dart';
 import 'build_aot.dart';
+import 'build_apk.dart';
 import 'build_flx.dart';
 import 'build_ios.dart';
 

packages/flutter_tools/lib/src/commands/build_apk.dart

@@ -20,8 +20,8 @@ import '../flx.dart' as flx;
 import '../globals.dart';
 import '../resident_runner.dart';
 import '../services.dart';
-import 'build_aot.dart';
 import 'build.dart';
+import 'build_aot.dart';
 
 export '../android/android_device.dart' show AndroidDevice;
 

packages/flutter_tools/lib/src/commands/config.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 import '../globals.dart';
-import '../usage.dart';
 import '../runner/flutter_command.dart';
+import '../usage.dart';
 
 class ConfigCommand extends FlutterCommand {
   ConfigCommand() {

packages/flutter_tools/lib/src/commands/drive.dart

@@ -6,8 +6,8 @@ import 'dart:async';
 
 import '../android/android_device.dart' show AndroidDevice;
 import '../application_package.dart';
-import '../base/file_system.dart';
 import '../base/common.dart';
+import '../base/file_system.dart';
 import '../base/platform.dart';
 import '../base/process.dart';
 import '../build_info.dart';

packages/flutter_tools/lib/src/commands/trace.dart

@@ -11,8 +11,8 @@ import '../base/utils.dart';
 import '../build_info.dart';
 import '../cache.dart';
 import '../globals.dart';
-import '../vmservice.dart';
 import '../runner/flutter_command.dart';
+import '../vmservice.dart';
 
 // Names of some of the Timeline events we care about.
 const String kFlutterEngineMainEnterEventName = 'FlutterEngineMainEnter';

packages/flutter_tools/lib/src/dependency_checker.dart

@@ -2,12 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'globals.dart';
-
+import 'asset.dart';
 import 'base/file_system.dart';
 import 'dart/dependencies.dart';
 import 'dart/package_map.dart';
-import 'asset.dart';
+import 'globals.dart';
 
 class DependencyChecker {
   final DartDependencySetBuilder builder;

packages/flutter_tools/lib/src/devfs.dart

@@ -5,12 +5,12 @@
 import 'dart:async';
 import 'dart:convert' show BASE64, UTF8;
 
+import 'asset.dart';
 import 'base/context.dart';
 import 'base/file_system.dart';
 import 'base/io.dart';
 import 'build_info.dart';
 import 'dart/package_map.dart';
-import 'asset.dart';
 import 'globals.dart';
 import 'vmservice.dart';
 

packages/flutter_tools/lib/src/doctor.dart

@@ -7,8 +7,8 @@ import 'dart:convert' show UTF8;
 
 import 'package:archive/archive.dart';
 
-import 'android/android_workflow.dart';
 import 'android/android_studio_validator.dart';
+import 'android/android_workflow.dart';
 import 'base/common.dart';
 import 'base/context.dart';
 import 'base/file_system.dart';

packages/flutter_tools/lib/src/flx.dart

@@ -9,9 +9,9 @@ import 'asset.dart';
 import 'base/common.dart';
 import 'base/file_system.dart';
 import 'base/process.dart';
+import 'build_info.dart';
 import 'dart/package_map.dart';
 import 'devfs.dart';
-import 'build_info.dart';
 import 'globals.dart';
 import 'zip.dart';
 

packages/flutter_tools/lib/src/ios/xcodeproj.dart

@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import '../artifacts.dart';
 import '../base/file_system.dart';
 import '../base/process.dart';
 import '../build_info.dart';
-import '../artifacts.dart';
 import '../cache.dart';
 import '../globals.dart';
 

packages/flutter_tools/lib/src/run_hot.dart

@@ -13,15 +13,13 @@ import 'base/file_system.dart';
 import 'base/logger.dart';
 import 'base/utils.dart';
 import 'build_info.dart';
-
 import 'dart/dependencies.dart';
 import 'devfs.dart';
 import 'device.dart';
 import 'globals.dart';
 import 'resident_runner.dart';
-
-import 'vmservice.dart';
 import 'usage.dart';
+import 'vmservice.dart';
 
 class HotRunnerConfig {
   /// Should the hot runner compute the minimal Dart dependencies?

packages/flutter_tools/lib/src/services.dart

@@ -7,9 +7,9 @@ import 'dart:convert';
 
 import 'package:yaml/yaml.dart';
 
+import 'android/android_sdk.dart';
 import 'base/file_system.dart';
 import 'dart/package_map.dart';
-import 'android/android_sdk.dart';
 import 'globals.dart';
 
 const String _kFlutterManifestPath = 'pubspec.yaml';

packages/flutter_tools/lib/src/zip.dart

@@ -6,9 +6,9 @@ import 'dart:async';
 
 import 'package:archive/archive.dart';
 
-import 'devfs.dart';
 import 'base/file_system.dart';
 import 'base/process.dart';
+import 'devfs.dart';
 
 abstract class ZipBuilder {
   factory ZipBuilder() {