Remove animation scheduler.

examples/rendering/spinning_flex.dart

@@ -4,8 +4,8 @@
 
 import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
 
 import 'lib/solid_color_box.dart';
 

examples/widgets/spinning_mixed.dart

@@ -4,9 +4,9 @@
 
 import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
 
 import 'package:flutter_rendering_examples/solid_color_box.dart';
 

packages/flutter/lib/animation.dart

@@ -12,7 +12,6 @@ export 'src/animation/performance.dart';
 export 'src/animation/clamped_simulation.dart';
 export 'src/animation/curves.dart';
 export 'src/animation/forces.dart';
-export 'src/animation/scheduler.dart';
 export 'src/animation/scroll_behavior.dart';
 export 'src/animation/simulation_stepper.dart';
 export 'src/animation/ticker.dart';

packages/flutter/lib/task.dart → packages/flutter/lib/scheduler.dart

@@ -2,11 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-/// The Flutter Task library.
+/// The Flutter Scheduler library.
 ///
-/// This library provides means to schedule tasks at given priorities.
-/// The library will make sure that tasks are only run when appropriate.
-/// For example, an idle-task will not run when an animation is running.
-library task;
+/// This library is responsible for scheduler frame callbacks, and tasks at
+/// given priorities.
+///
+/// The library makes sure that tasks are only run when appropriate.
+/// For example, an idle-task is only executed when no animation is running.
+library scheduler;
 
 export 'src/scheduler/scheduler.dart';

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

@@ -5,8 +5,8 @@
 import 'dart:typed_data';
 import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/gestures.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:mojo/bindings.dart' as bindings;
 import 'package:mojo/core.dart' as core;
 import 'package:sky_services/pointer/pointer.mojom.dart';

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

@@ -6,8 +6,8 @@ import 'dart:developer';
 import 'dart:math' as math;
 import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/gestures.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:vector_math/vector_math_64.dart';
 
 import 'debug.dart';

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

@@ -5,8 +5,8 @@
 import 'dart:developer';
 import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/painting.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:vector_math/vector_math_64.dart';
 
 import 'box.dart';

packages/flutter/lib/src/scheduler/scheduler.dart

@@ -7,7 +7,6 @@ import 'dart:developer';
 import 'dart:ui' as ui;
 
 import 'package:collection/priority_queue.dart';
-import 'package:flutter/animation.dart' as animation show scheduler;
 
 /// Slows down animations by this factor to help in development.
 double timeDilation = 1.0;
@@ -268,7 +267,7 @@ class DefaultSchedulingStrategy implements SchedulingStrategy {
   // interesting to provide more info (like, how long the task ran the last
   // time).
   bool shouldRunTaskWithPriority(int priority) {
-    if (animation.scheduler.transientCallbackCount > 0)
+    if (scheduler.transientCallbackCount > 0)
       return priority >= Priority.animation._value;
     return true;
   }

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

@@ -4,8 +4,8 @@
 
 import 'dart:developer';
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
 
 import 'framework.dart';
 

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

@@ -4,6 +4,7 @@
 
 import 'package:flutter/animation.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
 
 import 'basic.dart';
 import 'framework.dart';

packages/flutter_test/lib/src/widget_tester.dart

@@ -4,9 +4,9 @@
 
 import 'dart:ui' as ui;
 
-import 'package:flutter/animation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:flutter/widgets.dart';
 import 'package:quiver/testing/async.dart';
 import 'package:quiver/time.dart';

packages/unit/test/animation/scheduler_test.dart → packages/unit/test/scheduler/animation_test.dart

-import 'package:flutter/animation.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:test/test.dart';
 
 void main() {

packages/unit/test/scheduler/scheduler_test.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/task.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:test/test.dart';
 
 class TestStrategy implements SchedulingStrategy {

packages/unit/test/widget/animated_container_test.dart

@@ -3,8 +3,8 @@
 // found in the LICENSE file.
 
 import 'package:flutter_test/flutter_test.dart';
-import 'package:flutter/animation.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:flutter/widgets.dart';
 import 'package:test/test.dart';
 

packages/unit/test/widget/build_scope_test.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:flutter_test/flutter_test.dart';
-import 'package:flutter/animation.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:flutter/widgets.dart';
 import 'package:test/test.dart';