Add benchmark for platform views (#52717)

dev/benchmarks/platform_views_layout/README.md

+# platform_views_layout
+
+## Scrolling benchmark
+
+To run the scrolling benchmark on a device:
+
+```
+flutter drive --profile test_driver/scroll_perf.dart
+```
+
+Results should be in the file `build/platform_views_scroll_perf.timeline_summary.json`.
+
+More detailed logs should be in `build/platform_views_scroll_perf.timeline.json`.
+
+
+## Startup benchmark
+
+To measure startup time on a device:
+
+```
+flutter run --profile --trace-startup
+```
+
+Results should be in the logs.
+
+Additional results should be in the file `build/start_up_info.json`.

dev/benchmarks/platform_views_layout/android/app/build.gradle

+// 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.
+
+def localProperties = new Properties()
+def localPropertiesFile = rootProject.file('local.properties')
+if (localPropertiesFile.exists()) {
+    localPropertiesFile.withInputStream { stream ->
+        localProperties.load(stream)
+    }
+}
+
+def flutterRoot = localProperties.getProperty('flutter.sdk')
+if (flutterRoot == null) {
+    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
+}
+
+apply plugin: 'com.android.application'
+apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
+
+android {
+    compileSdkVersion 28
+
+    lintOptions {
+        disable 'InvalidPackage'
+    }
+
+    defaultConfig {
+        minSdkVersion 16
+        targetSdkVersion 28
+        versionCode 1
+        versionName "0.0.1"
+    }
+
+    buildTypes {
+        release {
+            // TODO: Add your own signing config for the release build.
+            // Signing with the debug keys for now, so `flutter run --release` works.
+            signingConfig signingConfigs.debug
+        }
+    }
+
+    aaptOptions {
+        // TODO(goderbauer): remove when https://github.com/flutter/flutter/issues/8986 is resolved.
+        if(System.getenv("FLUTTER_CI_WIN")) {
+            println "AAPT cruncher disabled when running on CI, see https://github.com/flutter/flutter/issues/8986"
+            cruncherEnabled false
+        }
+    }
+}
+
+flutter {
+    source '../..'
+}

dev/benchmarks/platform_views_layout/android/app/src/main/AndroidManifest.xml

+<!-- 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. -->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="dev.benchmarks.platform_views_layout">
+
+    <uses-permission android:name="android.permission.INTERNET"/>
+
+    <application android:name="io.flutter.app.FlutterApplication" android:label="platform_view_layout">
+        <activity android:name=".DummyPlatformViewActivity"
+                  android:launchMode="singleTop"
+                  android:theme="@android:style/Theme.Black.NoTitleBar"
+                  android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+                  android:hardwareAccelerated="true"
+                  android:windowSoftInputMode="adjustResize">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

dev/benchmarks/platform_views_layout/android/app/src/main/java/dev/bechmarks/platform_views_layout/DummyPlatformView.java

+// 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.
+
+package dev.benchmarks.platform_views;
+
+import android.content.Context;
+import android.graphics.Color;
+import android.view.View;
+import android.widget.TextView;
+import io.flutter.plugin.platform.PlatformView;
+
+public class DummyPlatformView implements PlatformView {
+    private final TextView textView;
+
+    @SuppressWarnings("unchecked")
+    DummyPlatformView(final Context context, int id) {
+        textView = new TextView(context);
+        textView.setTextSize(72);
+        textView.setBackgroundColor(Color.rgb(255, 255, 255));
+        textView.setText("DummyPlatformView");
+    }
+
+    @Override
+    public View getView() {
+        return textView;
+    }
+
+    @Override
+    public void dispose() {}
+}

dev/benchmarks/platform_views_layout/android/app/src/main/java/dev/bechmarks/platform_views_layout/DummyPlatformViewActivity.java

+// 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.
+
+package dev.benchmarks.platform_views;
+
+import androidx.annotation.NonNull;
+import io.flutter.embedding.android.FlutterActivity;
+import io.flutter.embedding.engine.FlutterEngine;
+
+public class DummyPlatformViewActivity extends FlutterActivity {
+    @Override
+    public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
+        flutterEngine
+            .getPlatformViewsController()
+            .getRegistry()
+            .registerViewFactory("benchmarks/platform_views_layout/DummyPlatformView", new DummyPlatformViewFactory());
+    }
+}

dev/benchmarks/platform_views_layout/android/app/src/main/java/dev/bechmarks/platform_views_layout/DummyPlatformViewFactory.java

+// 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.
+
+package dev.benchmarks.platform_views;
+
+import android.content.Context;
+import androidx.annotation.Nullable;
+import io.flutter.plugin.common.MessageCodec;
+import io.flutter.plugin.common.StringCodec;
+import io.flutter.plugin.platform.PlatformView;
+import io.flutter.plugin.platform.PlatformViewFactory;
+import java.nio.ByteBuffer;
+
+public final class DummyPlatformViewFactory extends PlatformViewFactory {
+    DummyPlatformViewFactory() {
+        super(
+            new MessageCodec<Object>() {
+                @Nullable
+                @Override
+                public ByteBuffer encodeMessage(@Nullable Object o) {
+                    if (o instanceof String) {
+                    return StringCodec.INSTANCE.encodeMessage((String) o);
+                    }
+                    return null;
+                }
+
+                @Nullable
+                @Override
+                public Object decodeMessage(@Nullable ByteBuffer byteBuffer) {
+                    return StringCodec.INSTANCE.decodeMessage(byteBuffer);
+                }
+            }
+        );
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public PlatformView create(Context context, int id, Object args) {
+        return new DummyPlatformView(context, id);
+    }
+}

dev/benchmarks/platform_views_layout/android/build.gradle

+// 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.
+
+buildscript {
+    repositories {
+        google()
+        jcenter()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.5.0'
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+rootProject.buildDir = '../build'
+subprojects {
+    project.buildDir = "${rootProject.buildDir}/${project.name}"
+}
+subprojects {
+    project.evaluationDependsOn(':app')
+}
+
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}

dev/benchmarks/platform_views_layout/android/gradle.properties

+org.gradle.jvmargs=-Xmx1536M
+android.useAndroidX=true
+android.enableJetifier=true
+android.enableR8=true

dev/benchmarks/platform_views_layout/android/gradle/wrapper/gradle-wrapper.properties

+#Fri Jun 23 08:50:38 CEST 2017
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-all.zip

dev/benchmarks/platform_views_layout/android/settings.gradle

+// 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.
+
+include ':app'

dev/benchmarks/platform_views_layout/ios/Flutter/AppFrameworkInfo.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+  <key>CFBundleDevelopmentRegion</key>
+  <string>$(DEVELOPMENT_LANGUAGE)</string>
+  <key>CFBundleExecutable</key>
+  <string>App</string>
+  <key>CFBundleIdentifier</key>
+  <string>io.flutter.flutter.app</string>
+  <key>CFBundleInfoDictionaryVersion</key>
+  <string>6.0</string>
+  <key>CFBundleName</key>
+  <string>App</string>
+  <key>CFBundlePackageType</key>
+  <string>FMWK</string>
+  <key>CFBundleShortVersionString</key>
+  <string>1.0</string>
+  <key>CFBundleSignature</key>
+  <string>????</string>
+  <key>CFBundleVersion</key>
+  <string>1.0</string>
+  <key>MinimumOSVersion</key>
+  <string>8.0</string>
+</dict>
+</plist>

dev/benchmarks/platform_views_layout/ios/Flutter/Flutter.xcconfig

+#include "Generated.xcconfig"

dev/benchmarks/platform_views_layout/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata

+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:Runner.xcodeproj">
+   </FileRef>
+</Workspace>

dev/benchmarks/platform_views_layout/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

dev/benchmarks/platform_views_layout/ios/Runner/AppDelegate.h

+// 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 <Flutter/Flutter.h>
+#import <UIKit/UIKit.h>
+
+@interface AppDelegate : FlutterAppDelegate
+
+@end

dev/benchmarks/platform_views_layout/ios/Runner/AppDelegate.m

+// 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.
+
+#include "AppDelegate.h"
+#include "DummyPlatformView.h"
+#include "GeneratedPluginRegistrant.h"
+
+@implementation AppDelegate
+
+- (BOOL)application:(UIApplication *)application
+    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+  [GeneratedPluginRegistrant registerWithRegistry:self];
+
+   NSObject<FlutterPluginRegistrar>* registrar =
+      [self registrarForPlugin:@"benchmarks/platform_views_layout/DummyPlatformViewPlugin"];
+
+  DummyPlatformViewFactory* dummyPlatformViewFactory = [[DummyPlatformViewFactory alloc] init];
+  [registrar registerViewFactory:dummyPlatformViewFactory
+                                withId:@"benchmarks/platform_views_layout/DummyPlatformView"
+      gestureRecognizersBlockingPolicy:FlutterPlatformViewGestureRecognizersBlockingPolicyEager];
+
+  // Override point for customization after application launch.
+  return [super application:application didFinishLaunchingWithOptions:launchOptions];
+}
+
+@end

dev/benchmarks/platform_views_layout/ios/Runner/Base.lproj/LaunchScreen.storyboard

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="Llm-lL-Icb"/>
+                        <viewControllerLayoutGuide type="bottom" id="xb3-aO-Qok"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+</document>

dev/benchmarks/platform_views_layout/ios/Runner/Base.lproj/Main.storyboard

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="BYZ-38-t0r">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
+    </dependencies>
+    <scenes>
+        <!--Flutter View Controller-->
+        <scene sceneID="tne-QT-ifu">
+            <objects>
+                <viewController id="BYZ-38-t0r" customClass="FlutterViewController" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
+                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
+            </objects>
+        </scene>
+    </scenes>
+</document>

dev/benchmarks/platform_views_layout/ios/Runner/DummyPlatformView.h

+// 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 <Flutter/Flutter.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface DummyPlatformView : NSObject <FlutterPlatformView>
+
+- (instancetype)initWithFrame:(CGRect)frame
+               viewIdentifier:(int64_t)viewId
+                    arguments:(id _Nullable)args
+              binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;
+
+- (UIView*)view;
+@end
+
+@interface DummyPlatformViewFactory : NSObject <FlutterPlatformViewFactory>
+- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;
+@end
+
+NS_ASSUME_NONNULL_END

dev/benchmarks/platform_views_layout/ios/Runner/DummyPlatformView.m

+// 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 "DummyPlatformView.h"
+
+@implementation DummyPlatformViewFactory {
+  NSObject<FlutterBinaryMessenger>* _messenger;
+}
+
+- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
+  self = [super init];
+  if (self) {
+    _messenger = messenger;
+  }
+  return self;
+}
+
+- (NSObject<FlutterPlatformView>*)createWithFrame:(CGRect)frame
+                                   viewIdentifier:(int64_t)viewId
+                                        arguments:(id _Nullable)args {
+  return [[DummyPlatformView alloc] initWithFrame:frame
+                                   viewIdentifier:viewId
+                                        arguments:args
+                                  binaryMessenger:_messenger];
+}
+
+- (NSObject<FlutterMessageCodec>*)createArgsCodec {
+  return [FlutterStringCodec sharedInstance];
+}
+
+@end
+
+@implementation DummyPlatformView {
+  UITextView* _view;
+  FlutterMethodChannel* _channel;
+}
+
+- (instancetype)initWithFrame:(CGRect)frame
+               viewIdentifier:(int64_t)viewId
+                    arguments:(id _Nullable)args
+              binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
+  if ([super init]) {
+    _view = [[UITextView alloc] initWithFrame:CGRectMake(0.0, 0.0, 250.0, 100.0)];
+    _view.textColor = UIColor.blueColor;
+    _view.backgroundColor = UIColor.lightGrayColor;
+    [_view setFont:[UIFont systemFontOfSize:52]];
+    _view.text = @"DummyPlatformView";
+  }
+  return self;
+}
+
+- (UIView*)view {
+  return _view;
+}
+
+@end

dev/benchmarks/platform_views_layout/ios/Runner/Info.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.yourcompany.complexLayout</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>complex_layout</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIMainStoryboardFile</key>
+	<string>Main</string>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UIViewControllerBasedStatusBarAppearance</key>
+	<false/>
+	<key>io.flutter.embedded_views_preview</key>
+	<true/>
+</dict>
+</plist>

dev/benchmarks/platform_views_layout/ios/Runner/main.m

+// 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 <UIKit/UIKit.h>
+#import <Flutter/Flutter.h>
+#import "AppDelegate.h"
+
+int main(int argc, char * argv[]) {
+    @autoreleasepool {
+        return UIApplicationMain(argc, argv, nil,
+                                 NSStringFromClass([AppDelegate class]));
+    }
+}

dev/benchmarks/platform_views_layout/lib/main.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:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart' show timeDilation;
+
+void main() {
+  runApp(
+    PlatformViewApp()
+  );
+}
+
+class PlatformViewApp extends StatefulWidget {
+  @override
+  PlatformViewAppState createState() => PlatformViewAppState();
+
+  static PlatformViewAppState of(BuildContext context) => context.findAncestorStateOfType<PlatformViewAppState>();
+}
+
+class PlatformViewAppState extends State<PlatformViewApp> {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      theme: ThemeData.light(),
+      title: 'Advanced Layout',
+      home: const PlatformViewLayout(),
+    );
+  }
+
+  void toggleAnimationSpeed() {
+    setState(() {
+      timeDilation = (timeDilation != 1.0) ? 1.0 : 5.0;
+    });
+  }
+}
+
+
+class PlatformViewLayout extends StatelessWidget {
+  const PlatformViewLayout({ Key key }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Platform View Scrolling Layout')),
+      body: ListView.builder(
+        key: const Key('platform-views-scroll'), // This key is used by the driver test.
+        itemCount: 200,
+        itemBuilder: (BuildContext context, int index) {
+          return Padding(
+            padding: const EdgeInsets.all(5.0),
+            child: Material(
+              elevation: (index % 5 + 1).toDouble(),
+              color: Colors.white,
+              child: Stack(
+                children: const <Widget> [
+                  DummyPlatformView(),
+                  RotationContainer(),
+                ],
+              ),
+            ),
+          );
+        },
+      ),
+    );
+  }
+}
+
+class DummyPlatformView extends StatelessWidget {
+  const DummyPlatformView({Key key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    const String viewType = 'benchmarks/platform_views_layout/DummyPlatformView';
+    StatefulWidget nativeView;
+    if (Platform.isIOS) {
+      nativeView = const UiKitView(
+        viewType: viewType,
+      );
+    } else if (Platform.isAndroid) {
+      nativeView = const AndroidView(
+        viewType: viewType,
+      );
+    } else {
+      assert(false, 'Invalid platform');
+    }
+    return Container(
+      color: Colors.purple,
+      height: 200.0,
+      child: nativeView,
+    );
+  }
+}
+
+class RotationContainer extends StatefulWidget {
+  const RotationContainer({Key key}) : super(key: key);
+
+  @override
+  _RotationContainerState createState() => _RotationContainerState();
+}
+
+class _RotationContainerState extends State<RotationContainer>
+  with SingleTickerProviderStateMixin {
+  AnimationController _rotationController;
+
+  @override
+  void initState() {
+    super.initState();
+    _rotationController = AnimationController(
+      vsync: this,
+      duration: const Duration(seconds: 1),
+      value: 1,
+    );
+    _rotationController.repeat();
+  }
+  @override
+  Widget build(BuildContext context) {
+    return RotationTransition(
+      turns: Tween<double>(begin: 0.0, end: 1.0).animate(_rotationController),
+      child: Container(
+        color: Colors.purple,
+        width: 50.0,
+        height: 50.0,
+      ),
+    );
+  }
+}

dev/benchmarks/platform_views_layout/pubspec.yaml

+name: platform_views_layout
+description: A benchmark for platform views.
+
+environment:
+  # The pub client defaults to an <2.0.0 sdk constraint which we need to explicitly overwrite.
+  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  flutter_driver:
+    sdk: flutter
+
+  # To change the version of the gallery assets, edit
+  #   //packages/flutter_tools/lib/src/commands/update_packages.dart
+  # and run
+  #   flutter update-packages --force-upgrade
+  flutter_gallery_assets: 0.1.9+2
+
+  archive: 2.0.11 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  args: 1.5.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  async: 2.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  charcode: 1.1.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  collection: 1.14.11 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  convert: 2.1.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  crypto: 2.1.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  file: 5.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  intl: 0.16.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  json_rpc_2: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  matcher: 0.12.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  meta: 1.1.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  path: 1.6.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pub_semver: 1.4.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_span: 1.5.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stack_trace: 1.9.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stream_channel: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  sync_http: 0.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vm_service_client: 0.2.6+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  web_socket_channel: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  webdriver: 2.1.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  test: 1.14.2
+
+  _fe_analyzer_shared: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  analyzer: 0.39.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  boolean_selector: 1.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  coverage: 0.13.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  csslib: 0.16.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  glob: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  html: 0.14.0+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http: 0.12.0+4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_multi_server: 2.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_parser: 3.1.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  image: 2.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  io: 0.3.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  js: 0.6.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  logging: 0.11.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  mime: 0.9.6+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  multi_server_socket: 1.0.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_interop: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_io: 1.0.1+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_preamble: 1.4.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_config: 1.9.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_resolver: 1.0.10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pedantic: 1.9.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  petitparser: 2.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pool: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  quiver: 2.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf: 0.7.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_packages_handler: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_static: 0.2.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_web_socket: 0.2.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_map_stack_trace: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_maps: 0.10.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  string_scanner: 1.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_api: 0.2.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.3.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vm_service: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  watcher: 0.9.7+14 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  webkit_inspection_protocol: 0.5.0+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  xml: 3.5.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  yaml: 2.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+
+flutter:
+  uses-material-design: true
+  assets:
+    - packages/flutter_gallery_assets/people/square/ali.png
+    - packages/flutter_gallery_assets/places/india_chettinad_silk_maker.png
+
+# PUBSPEC CHECKSUM: 2d9e

dev/benchmarks/platform_views_layout/test_driver/scroll_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:platform_views_layout/main.dart' as app;
+
+void main() {
+  enableFlutterDriverExtension();
+  app.main();
+}

dev/benchmarks/platform_views_layout/test_driver/scroll_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 'dart:async';
+
+import 'package:flutter_driver/flutter_driver.dart';
+import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
+
+void main() {
+  group('scrolling performance test', () {
+    FlutterDriver driver;
+
+    setUpAll(() async {
+      driver = await FlutterDriver.connect();
+
+      await driver.waitUntilFirstFrameRasterized();
+    });
+
+    tearDownAll(() async {
+      if (driver != null)
+        driver.close();
+    });
+
+    Future<void> testScrollPerf(String listKey, String summaryName) async {
+      // 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 Timeline timeline = await driver.traceAction(() async {
+        // Find the scrollable stock list
+        final SerializableFinder list = find.byValueKey(listKey);
+        expect(list, isNotNull);
+
+        // Scroll down
+        for (int i = 0; i < 5; i += 1) {
+          await driver.scroll(list, 0.0, -300.0, const Duration(milliseconds: 300));
+          await Future<void>.delayed(const Duration(milliseconds: 500));
+        }
+
+        // Scroll up
+        for (int i = 0; i < 5; i += 1) {
+          await driver.scroll(list, 0.0, 300.0, const Duration(milliseconds: 300));
+          await Future<void>.delayed(const Duration(milliseconds: 500));
+        }
+      });
+
+      final TimelineSummary summary = TimelineSummary.summarize(timeline);
+      summary.writeSummaryToFile(summaryName, pretty: true);
+      summary.writeTimelineToFile(summaryName, pretty: true);
+    }
+
+    test('platform_views_scroll_perf', () async {
+      // Disable frame sync, since there are ongoing animations.
+      await driver.runUnsynchronized(() async {
+        await testScrollPerf('platform-views-scroll', 'platform_views_scroll_perf');
+      });
+    });
+  });
+}

dev/devicelab/bin/tasks/platform_views_scroll_perf__timeline_summary.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 '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(createPlatformViewsScrollPerfTest());
+}

dev/devicelab/bin/tasks/platform_views_scroll_perf_ios__timeline_summary.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 '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(createPlatformViewsScrollPerfTest());
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -30,6 +30,14 @@ TaskFunction createTilesScrollPerfTest() {
   ).run;
 }
 
+TaskFunction createPlatformViewsScrollPerfTest() {
+  return PerfTest(
+    '${flutterDirectory.path}/dev/benchmarks/platform_views_layout',
+    'test_driver/scroll_perf.dart',
+    'platform_views_scroll_perf',
+  ).run;
+}
+
 TaskFunction createHomeScrollPerfTest() {
   return PerfTest(
     '${flutterDirectory.path}/dev/integration_tests/flutter_gallery',

dev/devicelab/manifest.yaml

@@ -147,6 +147,12 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
 
+  platform_views_scroll_perf__timeline_summary:
+    description: >
+      Measures the runtime performance of platform views in the Complex Layout sample app on Android.
+    stage: devicelab_ios
+    required_agent_capabilities: ["linux/android"]
+
   home_scroll_perf__timeline_summary:
     description: >
       Measures the runtime performance of scrolling the material page in the
@@ -439,6 +445,12 @@ tasks:
     # TODO(keyonghan): change with https://github.com/flutter/flutter/issues/50383
     required_agent_capabilities: ["mac/ios"]
 
+  platform_views_scroll_perf_ios__timeline_summary:
+    description: >
+      Measures the runtime performance of platform views in the Complex Layout sample app on iPhone 6.
+    stage: devicelab_ios
+    required_agent_capabilities: ["mac/ios"]
+
   flutter_gallery_ios32__start_up:
     description: >
       Measures the startup time of the Flutter Gallery app on 32-bit iOS (iPhone 4S).