Remove "unnecessary" imports. (#73486)

packages/flutter/lib/src/cupertino/app.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 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'button.dart';

packages/flutter/lib/src/cupertino/context_menu.dart

@@ -6,7 +6,6 @@ import 'dart:math' as math;
 import 'dart:ui' as ui;
 import 'package:flutter/gestures.dart' show kMinFlingVelocity, kLongPressTimeout;
 import 'package:flutter/foundation.dart' show kIsWeb;
-import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';

packages/flutter/lib/src/cupertino/context_menu_action.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 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 import 'colors.dart';
 

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

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui';
 
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/widgets.dart';

packages/flutter/lib/src/cupertino/debug.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 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'localizations.dart';

packages/flutter/lib/src/cupertino/form_row.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 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

packages/flutter/lib/src/cupertino/form_section.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 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';

packages/flutter/lib/src/cupertino/route.dart

@@ -5,7 +5,6 @@
 import 'dart:math';
 import 'dart:ui' show lerpDouble, ImageFilter;
 
-import 'package:flutter/animation.dart' show Curves;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';

packages/flutter/lib/src/cupertino/scrollbar.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 'package:flutter/gestures.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 

packages/flutter/lib/src/cupertino/search_field.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 'package:flutter/rendering.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 
 import 'button.dart';

packages/flutter/lib/src/cupertino/segmented_control.dart

@@ -5,7 +5,6 @@
 import 'dart:collection';
 import 'dart:math' as math;
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 

packages/flutter/lib/src/cupertino/sliding_segmented_control.dart

@@ -4,7 +4,6 @@
 
 import 'dart:math' as math;
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/physics.dart';
 import 'package:flutter/rendering.dart';

packages/flutter/lib/src/cupertino/tab_scaffold.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 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'bottom_tab_bar.dart';
 import 'colors.dart';

packages/flutter/lib/src/cupertino/text_form_field_row.dart

@@ -2,14 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';
 import 'form_row.dart';
 import 'text_field.dart';
-import 'theme.dart';
 
 /// Creates a [CupertinoFormRow] containing a [FormField] that wraps
 /// a [CupertinoTextField].

packages/flutter/lib/src/cupertino/text_selection.dart

@@ -8,7 +8,6 @@ import 'dart:ui' as ui;
 
 import 'package:flutter/widgets.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter/services.dart';
 
 import 'button.dart';
 import 'colors.dart';