Revert "Shader warm up (#27660)" (#28376)

This reverts commit a44f174e.

Reason: start_up tests become flaky.

See https://github.com/flutter/flutter/issues/28374

TBR: xster

Merge on red to fix the tree

dev/benchmarks/macrobenchmarks/lib/common.dart

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
 const String kCullOpacityRouteName = '/cull_opacity';
-const String kCubicBezierRouteName = '/cubic_bezier';

dev/benchmarks/macrobenchmarks/lib/main.dart

-// Copyright 2015 The Chromium 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 'package:flutter/material.dart';
 
 import 'common.dart';
-import 'src/cubic_bezier.dart';
 import 'src/cull_opacity.dart';
 
 const String kMacrobenchmarks ='Macrobenchmarks';
@@ -21,7 +16,6 @@ class MacrobenchmarksApp extends StatelessWidget {
       routes: <String, WidgetBuilder>{
         '/': (BuildContext context) => HomePage(),
         kCullOpacityRouteName: (BuildContext context) => CullOpacityPage(),
-        kCubicBezierRouteName: (BuildContext context) => CubicBezierPage(),
       },
     );
   }
@@ -40,13 +34,6 @@ class HomePage extends StatelessWidget {
             onPressed: (){
               Navigator.pushNamed(context, kCullOpacityRouteName);
             },
-          ),
-          RaisedButton(
-            key: const Key(kCubicBezierRouteName),
-            child: const Text('Cubic Bezier'),
-            onPressed: (){
-              Navigator.pushNamed(context, kCubicBezierRouteName);
-            },
           )
         ],
       ),

dev/benchmarks/macrobenchmarks/test_driver/cubic_bezier_perf.dart

-// Copyright 2018 The Chromium 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:ui';
-
-import 'package:flutter_driver/driver_extension.dart';
-import 'package:flutter/painting.dart' show DefaultShaderWarmUp, PaintingBinding;
-import 'package:macrobenchmarks/main.dart' as app;
-
-class CubicBezierShaderWarmUp extends DefaultShaderWarmUp {
-  @override
-  void warmUpOnCanvas(Canvas canvas) {
-    super.warmUpOnCanvas(canvas);
-
-    // Warm up the cubic shaders used by CubicBezierPage.
-    //
-    // This tests that our custom shader warm up is working properly.
-    // Without this custom shader warm up, the worst frame time is about 115ms.
-    // With this, the worst frame time is about 70ms. (Data collected on a Moto
-    // G4 based on Flutter version 704814c67a874077710524d30412337884bf0254.
-    final Path path = Path();
-    path.moveTo(20.0, 20.0);
-    // This cubic path is based on
-    // https://skia.org/user/api/SkPath_Reference#SkPath_cubicTo
-    path.cubicTo(300.0, 80.0, -140.0, 90.0, 220.0, 10.0);
-    final Paint paint = Paint();
-    paint.isAntiAlias = true;
-    paint.strokeWidth = 18.0;
-    paint.style = PaintingStyle.stroke;
-    paint.strokeCap = StrokeCap.round;
-    canvas.drawPath(path, paint);
-  }
-}
-
-void main() {
-  PaintingBinding.shaderWarmUp = CubicBezierShaderWarmUp();
-  enableFlutterDriverExtension();
-  app.main();
-}

dev/benchmarks/macrobenchmarks/test_driver/cubic_bezier_perf_test.dart

-// Copyright 2018 The Chromium 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 'package:macrobenchmarks/common.dart';
-
-import 'util.dart';
-
-void main() {
-  macroPerfTest('cubic_bezier_perf', kCubicBezierRouteName);
-}

dev/benchmarks/macrobenchmarks/test_driver/cull_opacity_perf_test.dart

@@ -2,15 +2,42 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:macrobenchmarks/common.dart';
+import 'dart:async';
+
+import 'package:flutter_driver/flutter_driver.dart';
+import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
 
-import 'util.dart';
+import 'package:macrobenchmarks/common.dart';
 
 void main() {
-  macroPerfTest(
-    'cull_opacity_perf',
-    kCullOpacityRouteName,
-    pageDelay: const Duration(seconds: 1),
-    duration: const Duration(seconds: 10)
-  );
+  const String kName = 'cull_opacity_perf';
+
+  test(kName, () async {
+    final FlutterDriver driver = await FlutterDriver.connect();
+
+    // The slight initial delay avoids starting the timing during a
+    // period of increased load on the device. Without this delay, the
+    // benchmark has greater noise.
+    // See: https://github.com/flutter/flutter/issues/19434
+    await Future<void>.delayed(const Duration(milliseconds: 250));
+
+    await driver.forceGC();
+
+    final SerializableFinder button = find.byValueKey(kCullOpacityRouteName);
+    expect(button, isNotNull);
+    await driver.tap(button);
+
+    // Wait for the page to load
+    await Future<void>.delayed(const Duration(seconds: 1));
+
+    final Timeline timeline = await driver.traceAction(() async {
+      await Future<void>.delayed(const Duration(seconds: 10));
+    });
+
+    final TimelineSummary summary = TimelineSummary.summarize(timeline);
+    summary.writeSummaryToFile(kName, pretty: true);
+    summary.writeTimelineToFile(kName, pretty: true);
+
+    driver.close();
+  });
 }

dev/benchmarks/macrobenchmarks/test_driver/util.dart

-// Copyright 2015 The Chromium 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_driver/flutter_driver.dart';
-import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
-
-void macroPerfTest(
-    String testName,
-    String routeName,
-    {Duration pageDelay, Duration duration = const Duration(seconds: 3)}) {
-  test(testName, () async {
-    final FlutterDriver driver = await FlutterDriver.connect();
-
-    // The slight initial delay avoids starting the timing during a
-    // period of increased load on the device. Without this delay, the
-    // benchmark has greater noise.
-    // See: https://github.com/flutter/flutter/issues/19434
-    await Future<void>.delayed(const Duration(milliseconds: 250));
-
-    await driver.forceGC();
-
-    final SerializableFinder button = find.byValueKey(routeName);
-    expect(button, isNotNull);
-    await driver.tap(button);
-
-    if (pageDelay != null) {
-      // Wait for the page to load
-      await Future<void>.delayed(pageDelay);
-    }
-
-    final Timeline timeline = await driver.traceAction(() async {
-      await Future<void>.delayed(duration);
-    });
-
-    final TimelineSummary summary = TimelineSummary.summarize(timeline);
-    summary.writeSummaryToFile(testName, pretty: true);
-    summary.writeTimelineToFile(testName, pretty: true);
-
-    driver.close();
-  });
-}

dev/devicelab/bin/tasks/cubic_bezier_perf__timeline_summary.dart

-// Copyright 2018 The Chromium 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(createCubicBezierPerfTest());
-}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -46,14 +46,6 @@ TaskFunction createCullOpacityPerfTest() {
   ).run;
 }
 
-TaskFunction createCubicBezierPerfTest() {
-  return PerfTest(
-    '${flutterDirectory.path}/dev/benchmarks/macrobenchmarks',
-    'test_driver/cubic_bezier_perf.dart',
-    'cubic_bezier_perf',
-  ).run;
-}
-
 TaskFunction createFlutterGalleryStartupTest() {
   return StartupTest(
     '${flutterDirectory.path}/examples/flutter_gallery',

dev/devicelab/manifest.yaml

@@ -134,13 +134,6 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
 
-  cubic_bezier_perf__timeline_summary:
-    description: >
-      Measures the runtime performance of cubic bezier animations on Android.
-    stage: devicelab
-    required_agent_capabilities: ["mac/android"]
-    flaky: true
-
   flavors_test:
     description: >
       Checks that flavored builds work on Android.

examples/layers/raw/shader_warm_up.dart

-// Copyright 2015 The Chromium 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 example shows the draw operations to warm up the GPU shaders by default.
-
-import 'dart:ui' as ui;
-
-import 'package:flutter/material.dart';
-import 'package:flutter/painting.dart' show DefaultShaderWarmUp;
-
-void beginFrame(Duration timeStamp) {
-  // PAINT
-  final ui.PictureRecorder recorder = ui.PictureRecorder();
-  final ui.Rect paintBounds = ui.Rect.fromLTRB(0, 0, 1000, 1000);
-  final ui.Canvas canvas = ui.Canvas(recorder, paintBounds);
-  final ui.Paint backgroundPaint = ui.Paint()..color = Colors.white;
-  canvas.drawRect(paintBounds, backgroundPaint);
-  const DefaultShaderWarmUp().warmUpOnCanvas(canvas);
-  final ui.Picture picture = recorder.endRecording();
-
-  // COMPOSITE
-  final ui.SceneBuilder sceneBuilder = ui.SceneBuilder()
-    ..pushClipRect(paintBounds)
-    ..addPicture(ui.Offset.zero, picture)
-    ..pop();
-  ui.window.render(sceneBuilder.build());
-}
-
-void main() {
-  ui.window.onBeginFrame = beginFrame;
-  ui.window.scheduleFrame();
-}

examples/layers/test/smoketests/raw/shader_warm_up_test.dart

-// Copyright 2017 The Chromium 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 'package:test_api/test_api.dart' hide TypeMatcher, isInstanceOf;
-
-import '../../../raw/shader_warm_up.dart' as demo;
-
-void main() {
-  test('layers smoketest for raw/shader_warm_up.dart', () {
-    demo.main();
-  });
-}

packages/flutter/lib/painting.dart

@@ -50,7 +50,6 @@ export 'src/painting/matrix_utils.dart';
 export 'src/painting/notched_shapes.dart';
 export 'src/painting/paint_utilities.dart';
 export 'src/painting/rounded_rectangle_border.dart';
-export 'src/painting/shader_warm_up.dart';
 export 'src/painting/shape_decoration.dart';
 export 'src/painting/stadium_border.dart';
 export 'src/painting/strut_style.dart';

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

@@ -8,7 +8,6 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart' show ServicesBinding;
 
 import 'image_cache.dart';
-import 'shader_warm_up.dart';
 
 const double _kDefaultDecodedCacheRatioCap = 0.0;
 
@@ -23,34 +22,12 @@ mixin PaintingBinding on BindingBase, ServicesBinding {
     super.initInstances();
     _instance = this;
     _imageCache = createImageCache();
-    if (shaderWarmUp != null) {
-      shaderWarmUp.execute();
-    }
   }
 
   /// The current [PaintingBinding], if one has been created.
   static PaintingBinding get instance => _instance;
   static PaintingBinding _instance;
 
-  /// [ShaderWarmUp] to be executed during [initInstances].
-  ///
-  /// If the application has scenes that require the compilation of complex
-  /// shaders that are not covered by [DefaultShaderWarmUp], it may cause jank
-  /// in the middle of an animation or interaction. In that case, set
-  /// [shaderWarmUp] to a custom [ShaderWarmUp] before calling [initInstances]
-  /// (usually before [runApp] for normal flutter apps, and before
-  /// [enableFlutterDriverExtension] for flutter drive tests). Paint the scene
-  /// in the custom [ShaderWarmUp] so Flutter can pre-compile and cache the
-  /// shaders during startup. The warm up is only costly (100ms-200ms,
-  /// depending on the shaders to compile) during the first run after the
-  /// installation or a data wipe. The warm up does not block the main thread
-  /// so there should be no "Application Not Responding" warning.
-  ///
-  /// Currently the warm-up happens synchronously on the GPU thread which means
-  /// the rendering of the first frame on the GPU thread will be postponed until
-  /// the warm-up is finished.
-  static ShaderWarmUp shaderWarmUp = const DefaultShaderWarmUp();
-
   /// The singleton that implements the Flutter framework's image cache.
   ///
   /// The cache is used internally by [ImageProvider] and should generally not

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

-// Copyright 2015 The Chromium 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:developer';
-import 'dart:ui' as ui;
-
-import 'package:flutter/foundation.dart';
-
-/// Interface for drawing an image to warm up Skia shader compilations.
-///
-/// When Skia first sees a certain type of draw operations on GPU, it needs to
-/// compile the corresponding shader. The compilation can be slow (20ms-200ms).
-/// Having that time as a startup latency is often better than having a jank in
-/// the middle of an animation.
-///
-/// Therefore, we use this during the [PaintingBinding.initInstances] call to
-/// move common shader compilations from animation time to startup time. By
-/// default, a [DefaultShaderWarmUp] is used. Create a custom [ShaderWarmUp]
-/// subclass to replace [PaintingBinding.shaderWarmUp] before
-/// [PaintingBinding.initInstances] is called. Usually, that can be done before
-/// calling [runApp].
-///
-/// This warm up needs to be run on each individual device because the shader
-/// compilation depends on the specific GPU hardware and driver a device has. It
-/// can't be pre-computed during the Flutter engine compilation as the engine is
-/// device agnostic.
-///
-/// If no warm up is desired (e.g., when the startup latency is crucial), set
-/// [PaintingBinding.shaderWarmUp] either to a custom ShaderWarmUp with an empty
-/// [warmUpOnCanvas] or null.
-abstract class ShaderWarmUp {
-  /// Allow const constructors for subclasses.
-  const ShaderWarmUp();
-
-  /// The size of the warm up image.
-  ///
-  /// The exact size shouldn't matter much as long as it's not too far away from
-  /// the target device's screen. 1024x1024 is a good choice as it is within an
-  /// order of magnitude of most devices.
-  ///
-  /// A custom shader warm up can override this based on targeted devices.
-  ui.Size get size => const ui.Size(1024.0, 1024.0);
-
-  /// Trigger draw operations on a given canvas to warm up GPU shader
-  /// compilation cache.
-  ///
-  /// To decide which draw operations to be added to your custom warm up
-  /// process, try capture an skp using `flutter screenshot --observatory-
-  /// port=<port> --type=skia` and analyze it with https://debugger.skia.org.
-  /// Alternatively, one may run the app with `flutter run --trace-skia` and
-  /// then examine the GPU thread in the observatory timeline to see which
-  /// Skia draw operations are commonly used, and which shader compilations
-  /// are causing janks.
-  @protected
-  void warmUpOnCanvas(ui.Canvas canvas);
-
-  /// Construct an offscreen image of [size], and execute [warmUpOnCanvas] on a
-  /// canvas associated with that image.
-  void execute() {
-    final ui.PictureRecorder recorder = ui.PictureRecorder();
-    final ui.Canvas canvas = ui.Canvas(recorder);
-
-    warmUpOnCanvas(canvas);
-
-    final ui.Picture picture = recorder.endRecording();
-    final TimelineTask shaderWarmUpTask = TimelineTask();
-    shaderWarmUpTask.start('Warm-up shader');
-    picture.toImage(size.width.ceil(), size.height.ceil()).then((ui.Image image) {
-      shaderWarmUpTask.finish();
-    });
-  }
-}
-
-/// Default way of warming up Skia shader compilations.
-///
-/// The draw operations being warmed up here are decided according to Flutter
-/// engineers' observation and experience based on the apps and the performance
-/// issues seen so far.
-class DefaultShaderWarmUp extends ShaderWarmUp {
-  /// Allow [DefaultShaderWarmUp] to be used as the default value of parameters.
-  const DefaultShaderWarmUp();
-
-  /// Trigger common draw operations on a canvas to warm up GPU shader
-  /// compilation cache.
-  @override
-  void warmUpOnCanvas(ui.Canvas canvas) {
-    final ui.RRect rrect = ui.RRect.fromLTRBXY(20.0, 20.0, 60.0, 60.0, 10.0, 10.0);
-    final ui.Path rrectPath = ui.Path()..addRRect(rrect);
-
-    final ui.Path circlePath = ui.Path()..addOval(
-        ui.Rect.fromCircle(center: const ui.Offset(40.0, 40.0), radius: 20.0)
-    );
-
-    // The following path is based on
-    // https://skia.org/user/api/SkCanvas_Reference#SkCanvas_drawPath
-    final ui.Path path = ui.Path();
-    path.moveTo(20.0, 60.0);
-    path.quadraticBezierTo(60.0, 20.0, 60.0, 60.0);
-    path.close();
-    path.moveTo(60.0, 20.0);
-    path.quadraticBezierTo(60.0, 60.0, 20.0, 60.0);
-
-    final List<ui.Path> paths = <ui.Path>[rrectPath, circlePath, path];
-
-    final List<ui.Paint> paints = <ui.Paint>[
-      ui.Paint()
-        ..isAntiAlias = true
-        ..style = ui.PaintingStyle.fill,
-      ui.Paint()
-        ..isAntiAlias = true
-        ..style = ui.PaintingStyle.stroke
-        ..strokeWidth = 10,
-      ui.Paint()
-        ..isAntiAlias = true
-        ..style = ui.PaintingStyle.stroke
-        ..strokeWidth = 0.1  // hairline
-    ];
-
-    // Warm up path stroke and fill shaders.
-    for (int i = 0; i < paths.length; i += 1) {
-      canvas.save();
-      for (ui.Paint paint in paints) {
-        canvas.drawPath(paths[i], paint);
-        canvas.translate(80.0, 0.0);
-      }
-      canvas.restore();
-      canvas.translate(0.0, 80.0);
-    }
-
-    // Warm up shadow shaders.
-    const ui.Color black = ui.Color(0xFF000000);
-    canvas.save();
-    canvas.drawShadow(rrectPath, black, 10.0, true);
-    canvas.translate(80.0, 0.0);
-    canvas.drawShadow(rrectPath, black, 10.0, false);
-    canvas.restore();
-
-    // Warm up text shaders.
-    canvas.translate(0.0, 80.0);
-    final ui.ParagraphBuilder paragraphBuilder = ui.ParagraphBuilder(
-      ui.ParagraphStyle(textDirection: ui.TextDirection.ltr),
-    )..pushStyle(ui.TextStyle(color: black))..addText('_');
-    final ui.Paragraph paragraph = paragraphBuilder.build()
-      ..layout(const ui.ParagraphConstraints(width: 60.0));
-    canvas.drawParagraph(paragraph, const ui.Offset(20.0, 20.0));
-  }
-}