Revert "A benchmark test case for measuring scroll smoothness (#61998)" (#64883)

This reverts commit 12b7355da11f4a1401492b16677f6e90ce0118b8.

dev/benchmarks/complex_layout/android/settings.gradle

@@ -3,13 +3,3 @@
 // found in the LICENSE file.
 
 include ':app'
-
-def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
-def properties = new Properties()
-
-assert localPropertiesFile.exists()
-localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
-
-def flutterSdkPath = properties.getProperty("flutter.sdk")
-assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
-apply from: "$flutterSdkPath/packages/flutter_tools/gradle/app_plugin_loader.gradle"

dev/benchmarks/complex_layout/lib/main.dart

@@ -109,7 +109,6 @@ class ComplexLayoutState extends State<ComplexLayout> {
           Expanded(
             child: ListView.builder(
               key: const Key('complex-scroll'), // this key is used by the driver test
-              controller: ScrollController(),  // So that the scroll offset can be tracked
               itemBuilder: (BuildContext context, int index) {
                 if (index % 2 == 0)
                   return FancyImageItem(index, key: PageStorageKey<int>(index));

dev/benchmarks/complex_layout/pubspec.yaml

@@ -3,7 +3,7 @@ description: A benchmark of a relatively complex layout.
 
 environment:
   # The pub client defaults to an <2.0.0 sdk constraint which we need to explicitly overwrite.
-  sdk: ">=2.2.2 <3.0.0"
+  sdk: ">=2.0.0-dev.68.0 <3.0.0"
 
 dependencies:
   flutter:
@@ -46,7 +46,6 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
   test: 1.16.0-nullsafety.1
-  e2e: 0.7.0
 
   _fe_analyzer_shared: 7.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   analyzer: 0.39.17 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -91,4 +90,4 @@ flutter:
     - packages/flutter_gallery_assets/people/square/ali.png
     - packages/flutter_gallery_assets/places/india_chettinad_silk_maker.png
 
-# PUBSPEC CHECKSUM: 047d
+# PUBSPEC CHECKSUM: 6832

dev/benchmarks/complex_layout/test/measure_scroll_smoothness.dart

@@ -1,296 +0,0 @@
-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This test is a use case of flutter/flutter#60796
-// the test should be run as:
-// flutter drive -t test/using_array.dart --driver test_driver/scrolling_test_e2e_test.dart
-
-import 'dart:ui' as ui;
-
-import 'package:flutter/gestures.dart';
-import 'package:flutter/material.dart';
-import 'package:flutter_test/flutter_test.dart';
-import 'package:e2e/e2e.dart';
-
-import 'package:complex_layout/main.dart' as app;
-
-class PointerDataTestBinding extends E2EWidgetsFlutterBinding {
-  // PointerData injection would usually be considered device input and therefore
-  // blocked by [TestWidgetsFlutterBinding]. Override this behavior
-  // to help events go into widget tree.
-  @override
-  void dispatchEvent(
-    PointerEvent event,
-    HitTestResult hitTestResult, {
-    TestBindingEventSource source = TestBindingEventSource.device,
-  }) {
-    super.dispatchEvent(event, hitTestResult, source: TestBindingEventSource.test);
-  }
-}
-
-/// A union of [ui.PointerDataPacket] and the time it should be sent.
-class PointerDataRecord {
-  PointerDataRecord(this.timeStamp, List<ui.PointerData> data)
-    : data = ui.PointerDataPacket(data: data);
-  final ui.PointerDataPacket data;
-  final Duration timeStamp;
-}
-
-/// Generates the [PointerDataRecord] to simulate a drag operation from
-/// `center - totalMove/2` to `center + totalMove/2`.
-Iterable<PointerDataRecord> dragInputDatas(
-  final Duration epoch,
-  final Offset center, {
-  final Offset totalMove = const Offset(0, -400),
-  final Duration totalTime = const Duration(milliseconds: 2000),
-  final double frequency = 90,
-}) sync* {
-  final Offset startLocation = (center - totalMove / 2) * ui.window.devicePixelRatio;
-  // The issue is about 120Hz input on 90Hz refresh rate device.
-  // We test 90Hz input on 60Hz device here, which shows similar pattern.
-  final int moveEventCount = totalTime.inMicroseconds * frequency ~/ const Duration(seconds: 1).inMicroseconds;
-  final Offset movePerEvent = totalMove / moveEventCount.toDouble() * ui.window.devicePixelRatio;
-  yield PointerDataRecord(epoch, <ui.PointerData>[
-    ui.PointerData(
-      timeStamp: epoch,
-      change: ui.PointerChange.add,
-      physicalX: startLocation.dx,
-      physicalY: startLocation.dy,
-    ),
-    ui.PointerData(
-      timeStamp: epoch,
-      change: ui.PointerChange.down,
-      physicalX: startLocation.dx,
-      physicalY: startLocation.dy,
-      pointerIdentifier: 1,
-    ),
-  ]);
-  for (int t = 0; t < moveEventCount + 1; t++) {
-    final Offset position = startLocation + movePerEvent * t.toDouble();
-    yield PointerDataRecord(
-      epoch + totalTime * t ~/ moveEventCount,
-      <ui.PointerData>[ui.PointerData(
-        timeStamp: epoch + totalTime * t ~/ moveEventCount,
-        change: ui.PointerChange.move,
-        physicalX: position.dx,
-        physicalY: position.dy,
-        // Scrolling behavior depends on this delta rather
-        // than the position difference.
-        physicalDeltaX: movePerEvent.dx,
-        physicalDeltaY: movePerEvent.dy,
-        pointerIdentifier: 1,
-      )],
-    );
-  }
-  final Offset position = startLocation + totalMove;
-  yield PointerDataRecord(epoch + totalTime, <ui.PointerData>[ui.PointerData(
-    timeStamp: epoch + totalTime,
-    change: ui.PointerChange.up,
-    physicalX: position.dx,
-    physicalY: position.dy,
-    pointerIdentifier: 1,
-  )]);
-}
-
-enum TestScenario {
-  resampleOn90Hz,
-  resampleOn59Hz,
-  resampleOff90Hz,
-  resampleOff59Hz,
-}
-
-class ResampleFlagVariant extends TestVariant<TestScenario> {
-  ResampleFlagVariant(this.binding);
-  final E2EWidgetsFlutterBinding binding;
-
-  @override
-  final Set<TestScenario> values = Set<TestScenario>.from(TestScenario.values);
-
-  TestScenario currentValue;
-  bool get resample {
-    switch(currentValue) {
-      case TestScenario.resampleOn90Hz:
-      case TestScenario.resampleOn59Hz:
-        return true;
-      case TestScenario.resampleOff90Hz:
-      case TestScenario.resampleOff59Hz:
-        return false;
-    }
-    throw ArgumentError;
-  }
-  double get frequency {
-    switch(currentValue) {
-      case TestScenario.resampleOn90Hz:
-      case TestScenario.resampleOff90Hz:
-        return 90.0;
-      case TestScenario.resampleOn59Hz:
-      case TestScenario.resampleOff59Hz:
-        return 59.0;
-    }
-    throw ArgumentError;
-  }
-
-  Map<String, dynamic> result;
-
-  @override
-  String describeValue(TestScenario value) {
-    switch(value) {
-      case TestScenario.resampleOn90Hz:
-        return 'resample on with 90Hz input';
-      case TestScenario.resampleOn59Hz:
-        return 'resample on with 59Hz input';
-      case TestScenario.resampleOff90Hz:
-        return 'resample off with 90Hz input';
-      case TestScenario.resampleOff59Hz:
-        return 'resample off with 59Hz input';
-    }
-    throw ArgumentError;
-  }
-
-  @override
-  Future<bool> setUp(TestScenario value) async {
-    currentValue = value;
-    final bool original = binding.resamplingEnabled;
-    binding.resamplingEnabled = resample;
-    return original;
-  }
-
-  @override
-  Future<void> tearDown(TestScenario value, bool memento) async {
-    binding.resamplingEnabled = memento;
-    binding.reportData[describeValue(value)] = result;
-  }
-}
-
-Future<void> main() async {
-  final PointerDataTestBinding binding = PointerDataTestBinding();
-  assert(WidgetsBinding.instance == binding);
-  binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.benchmarkLive;
-  binding.reportData ??= <String, dynamic>{};
-  final ResampleFlagVariant variant = ResampleFlagVariant(binding);
-  testWidgets('Smoothness test', (WidgetTester tester) async {
-    app.main();
-    await tester.pumpAndSettle();
-    final Finder scrollerFinder = find.byKey(const ValueKey<String>('complex-scroll'));
-    final ListView scroller = tester.widget<ListView>(scrollerFinder);
-    final ScrollController controller = scroller.controller;
-    final List<int> frameTimestamp = <int>[];
-    final List<double> scrollOffset = <double>[];
-    final List<Duration> delays = <Duration>[];
-    binding.addPersistentFrameCallback((Duration timeStamp) {
-      if (controller.hasClients) {
-        // This if is necessary because by the end of the test the widget tree
-        // is destroyed.
-        frameTimestamp.add(timeStamp.inMicroseconds);
-        scrollOffset.add(controller.offset);
-      }
-    });
-
-    Duration now() => binding.currentSystemFrameTimeStamp;
-    Future<void> scroll() async {
-      // Extra 50ms to avoid timeouts.
-      final Duration startTime = const Duration(milliseconds: 500) + now();
-      for (final PointerDataRecord record in dragInputDatas(
-        startTime,
-        tester.getCenter(scrollerFinder),
-        frequency: variant.frequency,
-      )) {
-        await tester.binding.delayed(record.timeStamp - now());
-        // This now measures how accurate the above delayed is.
-        final Duration delay = now() - record.timeStamp;
-        if (delays.length < frameTimestamp.length) {
-          while (delays.length < frameTimestamp.length - 1) {
-            delays.add(Duration.zero);
-          }
-          delays.add(delay);
-        } else if (delays.last < delay) {
-          delays.last = delay;
-        }
-        ui.window.onPointerDataPacket(record.data);
-      }
-    }
-
-    for (int n = 0; n < 5; n++) {
-      await scroll();
-    }
-    variant.result = scrollSummary(scrollOffset, delays, frameTimestamp);
-    await tester.pumpAndSettle();
-    scrollOffset.clear();
-    delays.clear();
-    await tester.idle();
-  }, semanticsEnabled: false, variant: variant);
-}
-
-/// Calculates the smoothness measure from `scrollOffset` and `delays` list.
-///
-/// Smoothness (`abs_jerk`) is measured by  the absolute value of the discrete
-/// 2nd derivative of the scroll offset.
-///
-/// It was experimented that jerk (3rd derivative of the position) is a good
-/// measure the smoothness.
-/// Here we are using 2nd derivative instead because the input is completely
-/// linear and the expected acceleration should be strictly zero.
-/// Observed acceleration is jumping from positive to negative within
-/// adjacent frames, meaning mathematically the discrete 3-rd derivative
-/// (`f[3] - 3*f[2] + 3*f[1] - f[0]`) is not a good approximation of jerk
-/// (continuous 3-rd derivative), while discrete 2nd
-/// derivative (`f[2] - 2*f[1] + f[0]`) on the other hand is a better measure
-/// of how the scrolling deviate away from linear, and given the acceleration
-/// should average to zero within two frames, it's also a good approximation
-/// for jerk in terms of physics.
-/// We use abs rather than square because square (2-norm) amplifies the
-/// effect of the data point that's relatively large, but in this metric
-/// we prefer smaller data point to have similar effect.
-/// This is also why we count the number of data that's larger than a
-/// threshold (and the result is tested not sensitive to this threshold),
-/// which is effectively a 0-norm.
-///
-/// Frames that are too slow to build (longer than 40ms) or with input delay
-/// longer than 16ms (1/60Hz) is filtered out to separate the janky due to slow
-/// response.
-///
-/// The returned map has keys:
-/// `average_abs_jerk`: average for the overall smoothness.
-/// `janky_count`: number of frames with `abs_jerk` larger than 0.5.
-/// `dropped_frame_count`: number of frames that are built longer than 40ms and
-///  are not used for smoothness measurement.
-/// `frame_timestamp`: the list of the timestamp for each frame, in the time
-/// order.
-/// `scroll_offset`: the scroll offset for each frame. Its length is the same as
-/// `frame_timestamp`.
-/// `input_delay`: the list of maximum delay time of the input simulation during
-/// a frame. Its length is the same as `frame_timestamp`
-Map<String, dynamic> scrollSummary(
-  List<double> scrollOffset,
-  List<Duration> delays,
-  List<int> frameTimestamp,
-) {
-  double jankyCount = 0;
-  double absJerkAvg = 0;
-  int lostFrame = 0;
-  for (int i = 1; i < scrollOffset.length-1; i += 1) {
-    if (frameTimestamp[i+1] - frameTimestamp[i-1] > 40E3 ||
-        (i >= delays.length || delays[i] > const Duration(milliseconds: 16))) {
-      // filter data points from slow frame building or input simulation artifact
-      lostFrame += 1;
-      continue;
-    }
-    //
-    final double absJerk = (scrollOffset[i-1] + scrollOffset[i+1] - 2*scrollOffset[i]).abs();
-    absJerkAvg += absJerk;
-    if (absJerk > 0.5)
-      jankyCount += 1;
-  }
-  // expect(lostFrame < 0.1 * frameTimestamp.length, true);
-  absJerkAvg /= frameTimestamp.length - lostFrame;
-
-  return <String, dynamic>{
-    'janky_count': jankyCount,
-    'average_abs_jerk': absJerkAvg,
-    'dropped_frame_count': lostFrame,
-    'frame_timestamp': List<int>.from(frameTimestamp),
-    'scroll_offset': List<double>.from(scrollOffset),
-    'input_delay': delays.map<int>((Duration data) => data.inMicroseconds).toList(),
-  };
-}

dev/benchmarks/complex_layout/test_driver/measure_scroll_smoothness_test.dart

@@ -1,17 +0,0 @@
-// Copyright 2014 The Flutter 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 'package:e2e/e2e_driver.dart' as driver;
-
-Future<void> main() => driver.e2eDriver(
-  timeout: const Duration(minutes: 5),
-  responseDataCallback: (Map<String, dynamic> data) async {
-    await driver.writeResponseData(
-      data,
-      testOutputFilename: 'scroll_smoothness_test',
-    );
-  }
-);

dev/devicelab/bin/tasks/complex_layout_android__scroll_smoothness.dart

@@ -1,14 +0,0 @@
-// Copyright 2014 The Flutter 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 'package:flutter_devicelab/tasks/perf_tests.dart';
-import 'package:flutter_devicelab/framework/adb.dart';
-import 'package:flutter_devicelab/framework/framework.dart';
-
-Future<void> main() async {
-  deviceOperatingSystem = DeviceOperatingSystem.android;
-  await task(createsScrollSmoothnessPerfTest());
-}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -298,54 +298,6 @@ TaskFunction createsMultiWidgetConstructPerfE2ETest() {
   ).run;
 }
 
-TaskFunction createsScrollSmoothnessPerfTest() {
-  final String testDirectory =
-      '${flutterDirectory.path}/dev/benchmarks/complex_layout';
-  const String testTarget = 'test/measure_scroll_smoothness.dart';
-  return () {
-    return inDirectory<TaskResult>(testDirectory, () async {
-      final Device device = await devices.workingDevice;
-      await device.unlock();
-      final String deviceId = device.deviceId;
-      await flutter('packages', options: <String>['get']);
-
-      await flutter('drive', options: <String>[
-        '-v',
-        '--verbose-system-logs',
-        '--profile',
-        '-t', testTarget,
-        '-d',
-        deviceId,
-      ]);
-      final Map<String, dynamic> data = json.decode(
-        file('$testDirectory/build/scroll_smoothness_test.json').readAsStringSync(),
-      ) as Map<String, dynamic>;
-
-      final Map<String, dynamic> result = <String, dynamic>{};
-      void addResult(dynamic data, String suffix) {
-        assert(data is Map<String, dynamic>);
-        const List<String> metricKeys = <String>[
-          'janky_count',
-          'average_abs_jerk',
-          'dropped_frame_count',
-        ];
-        for (final String key in metricKeys) {
-          result[key+suffix] = data[key];
-        }
-      }
-      addResult(data['resample on with 90Hz input'], '_with_resampler_90Hz');
-      addResult(data['resample on with 59Hz input'], '_with_resampler_59Hz');
-      addResult(data['resample off with 90Hz input'], '_without_resampler_90Hz');
-      addResult(data['resample off with 59Hz input'], '_without_resampler_59Hz');
-
-      return TaskResult.success(
-        result,
-        benchmarkScoreKeys: result.keys.toList(),
-      );
-    });
-  };
-}
-
 TaskFunction createFramePolicyIntegrationTest() {
   final String testDirectory =
       '${flutterDirectory.path}/dev/benchmarks/macrobenchmarks';

dev/devicelab/manifest.yaml

@@ -114,14 +114,6 @@ tasks:
 
   # Android on-device tests
 
-  complex_layout_android__scroll_smoothness:
-    description: >
-      Measures the smoothness of scrolling of the Complex Layout sample app on
-      Android.
-    stage: devicelab
-    required_agent_capabilities: ["linux/android"]
-    flaky: true
-
   complex_layout_scroll_perf__timeline_summary:
     description: >
       Measures the runtime performance of the Complex Layout sample app on

packages/flutter_test/lib/src/binding.dart

@@ -1504,6 +1504,7 @@ class LiveTestWidgetsFlutterBinding extends TestWidgetsFlutterBinding {
             renderView._pointers[event.pointer].decay = _kPointerDecay;
           _handleViewNeedsPaint();
         } else if (event.down) {
+          assert(event is PointerDownEvent);
           renderView._pointers[event.pointer] = _LiveTestPointerRecord(
             event.pointer,
             event.position,