Reland test (#50987)

dev/benchmarks/macrobenchmarks/lib/common.dart

@@ -10,3 +10,4 @@ const String kSimpleAnimationRouteName = '/simple_animation';
 const String kPictureCacheRouteName = '/picture_cache';
 const String kLargeImagesRouteName = '/large_images';
 const String kTextRouteName = '/text';
+const String kAnimatedPlaceholderRouteName = '/animated_placeholder';

dev/benchmarks/macrobenchmarks/lib/main.dart

@@ -7,6 +7,7 @@ import 'package:macrobenchmarks/src/large_images.dart';
 import 'package:macrobenchmarks/src/picture_cache.dart';
 
 import 'common.dart';
+import 'src/animated_placeholder.dart';
 import 'src/backdrop_filter.dart';
 import 'src/cubic_bezier.dart';
 import 'src/cull_opacity.dart';
@@ -14,7 +15,7 @@ import 'src/post_backdrop_filter.dart';
 import 'src/simple_animation.dart';
 import 'src/text.dart';
 
-const String kMacrobenchmarks ='Macrobenchmarks';
+const String kMacrobenchmarks = 'Macrobenchmarks';
 
 void main() => runApp(const MacrobenchmarksApp());
 
@@ -36,6 +37,7 @@ class MacrobenchmarksApp extends StatelessWidget {
         kPictureCacheRouteName: (BuildContext context) => PictureCachePage(),
         kLargeImagesRouteName: (BuildContext context) => LargeImagesPage(),
         kTextRouteName: (BuildContext context) => TextPage(),
+        kAnimatedPlaceholderRouteName: (BuildContext context) => AnimatedPlaceholderPage(),
       },
     );
   }
@@ -106,6 +108,13 @@ class HomePage extends StatelessWidget {
               Navigator.pushNamed(context, kTextRouteName);
             },
           ),
+          RaisedButton(
+            key: const Key(kAnimatedPlaceholderRouteName),
+            child: const Text('Animated Placeholder'),
+            onPressed: () {
+              Navigator.pushNamed(context, kAnimatedPlaceholderRouteName);
+            },
+          ),
         ],
       ),
     );

dev/benchmarks/macrobenchmarks/lib/src/animated_placeholder.dart

+// 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 'dart:convert';
+import 'dart:ui' as ui show Codec;
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+/// An animated GIF image with 3 1x1 pixel frames (a red, green, and blue
+/// frames). The GIF animates forever, and each frame has a 100ms delay.
+const String kAnimatedGif = 'R0lGODlhAQABAKEDAAAA//8AAAD/AP///yH/C05FVFNDQVBFMi'
+                            '4wAwEAAAAh+QQACgD/ACwAAAAAAQABAAACAkwBACH5BAAKAP8A'
+                            'LAAAAAABAAEAAAICVAEAIfkEAAoA/wAsAAAAAAEAAQAAAgJEAQ'
+                            'A7';
+
+/// A 50x50 blue square png
+const String kBlueSquare = 'iVBORw0KGgoAAAANSUhEUgAAADIAAAAyCAYAAAAeP4ixAAAASEl'
+                           'EQVR42u3PMQ0AMAgAsGFjL/4tYQU08JLWQSN/9TsgRERERERERE'
+                           'REREREREREREREREREREREREREREREREREREREREQ2BgNuaUcSj'
+                           'uqqAAAAAElFTkSuQmCC';
+
+/// A 10x10 grid of animated looping placeholder gifts that fade into a
+/// blue square.
+class AnimatedPlaceholderPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return GridView.builder(
+      itemCount: 100,
+      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 10),
+      itemBuilder: (BuildContext context, int index) {
+        return FadeInImage(
+          placeholder: DelayedBase64Image(Duration.zero, kAnimatedGif),
+          image: DelayedBase64Image(Duration(milliseconds: 100 * index), kBlueSquare),
+        );
+      },
+    );
+  }
+}
+
+int _key = 0;
+/// An image provider that is always unique from other DelayedBase64Images and
+/// simulates a delay in loading.
+class DelayedBase64Image extends ImageProvider<int> {
+  const DelayedBase64Image(this.delay, this.data);
+
+  final String data;
+
+  final Duration delay;
+
+  @override
+  Future<int> obtainKey(ImageConfiguration configuration) {
+    return SynchronousFuture<int>(_key++);
+  }
+
+  @override
+  ImageStreamCompleter load(int key, DecoderCallback decode) {
+    return MultiFrameImageStreamCompleter(
+      codec: Future<ui.Codec>.delayed(
+        delay,
+        () => decode(base64.decode(data)),
+      ),
+      scale: 1.0,
+    );
+  }
+}

dev/benchmarks/macrobenchmarks/test_driver/animated_placeholder_perf.dart

+// 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 'package:flutter_driver/driver_extension.dart';
+import 'package:macrobenchmarks/main.dart' as app;
+
+void main() {
+  enableFlutterDriverExtension();
+  app.main();
+}

dev/benchmarks/macrobenchmarks/test_driver/animated_placeholder_perf_test.dart

+// 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 'package:macrobenchmarks/common.dart';
+
+import 'util.dart';
+
+void main() {
+  macroPerfTest(
+    'animated_placeholder_perf',
+    kAnimatedPlaceholderRouteName,
+    pageDelay: const Duration(seconds: 1),
+    duration: const Duration(seconds: 15),
+  );
+}

dev/devicelab/bin/tasks/animated_placeholder_perf.dart

+// 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 'package:flutter_devicelab/framework/adb.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+import 'package:flutter_devicelab/tasks/perf_tests.dart';
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.android;
+  await task(createAnimatedPlaceholderPerfTest());
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -81,6 +81,15 @@ TaskFunction createSimpleAnimationPerfTest({bool needsMeasureCpuGpu = false}) {
   ).run;
 }
 
+TaskFunction createAnimatedPlaceholderPerfTest({bool needsMeasureCpuGpu = false}) {
+  return PerfTest(
+    '${flutterDirectory.path}/dev/benchmarks/macrobenchmarks',
+    'test_driver/animated_placeholder_perf.dart',
+    'animated_placeholder_perf',
+    needsMeasureCpuGPu: needsMeasureCpuGpu,
+  ).run;
+}
+
 TaskFunction createPictureCachePerfTest() {
   return PerfTest(
     '${flutterDirectory.path}/dev/benchmarks/macrobenchmarks',

dev/devicelab/manifest.yaml

@@ -700,6 +700,15 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
 
+  animated_placeholder_perf:
+    description: >
+      Measures frame build and rasterizer times, as well as frame build counts
+      for a grid of images that uses FadeInImage with an animated gif as the
+      placeholder.
+    stage: devicelab
+    required_agent_capabilities: ["linux/android"]
+    flaky: true
+
   analyzer_benchmark:
     description: >
       Measures the speed of Dart analyzer.