[ios]A typical news app benchmark with bottom ad banner (#150991)

This is a very common usage of ad so we want to make sure it's performant. 

From the video, it scrolls quite smoothly, but we want to see the numbers, and keep monitoring it in case of regression.

https://github.com/flutter/flutter/assets/41930132/c7811c15-ac07-4989-a8a9-3c128e08cbe0

*List which issues are fixed by this PR. You must list at least one issue. An issue is not required if the PR fixes something trivial like a typo.*

Fixes https://github.com/flutter/flutter/issues/150230

*If you had to change anything in the [flutter/tests] repo, include a link to the migration guide as per the [breaking change policy].*

.ci.yaml

@@ -4808,6 +4808,16 @@ targets:
         ["devicelab", "ios", "mac"]
       task_name: platform_views_scroll_perf_ad_banners__timeline_summary
 
+  - name: Mac_ios platform_views_scroll_perf_bottom_ad_banner__timeline_summary
+    recipe: devicelab/devicelab_drone
+    presubmit: false
+    bringup: true
+    timeout: 60
+    properties:
+      tags: >
+        ["devicelab", "ios", "mac"]
+      task_name: platform_views_scroll_perf_bottom_ad_banner__timeline_summary
+
   - name: Mac_ios platform_views_scroll_perf_non_intersecting_impeller_ios__timeline_summary
     recipe: devicelab/devicelab_drone
     presubmit: false

TESTOWNERS

@@ -211,6 +211,7 @@
 /dev/devicelab/bin/tasks/platform_interaction_test_ios.dart @hellohuanlin @flutter/engine
 /dev/devicelab/bin/tasks/platform_view_ios__start_up.dart @stuartmorgan @flutter/plugin
 /dev/devicelab/bin/tasks/platform_views_scroll_perf_ad_banners__timeline_summary.dart @hellohuanlin @flutter/engine
+/dev/devicelab/bin/tasks/platform_views_scroll_perf_bottom_ad_banner__timeline_summary.dart @hellohuanlin @flutter/engine
 /dev/devicelab/bin/tasks/platform_views_scroll_perf_ios__timeline_summary.dart @hellohuanlin @flutter/engine
 /dev/devicelab/bin/tasks/platform_views_scroll_perf_non_intersecting_impeller_ios__timeline_summary.dart @jonahwilliams @flutter/engine
 /dev/devicelab/bin/tasks/post_backdrop_filter_perf_ios__timeline_summary.dart @hellohuanlin @flutter/engine

dev/benchmarks/platform_views_layout/lib/main_bottom_ad_banner.dart

@@ -0,0 +1,83 @@
+// 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:google_mobile_ads/google_mobile_ads.dart';
+
+void main() {
+  runApp(
+      const PlatformViewApp()
+  );
+}
+
+class PlatformViewApp extends StatefulWidget {
+  const PlatformViewApp({
+    super.key,
+  });
+
+  @override
+  PlatformViewAppState createState() => PlatformViewAppState();
+}
+
+class PlatformViewAppState extends State<PlatformViewApp> {
+
+  Widget _getBannerWidget() {
+    // Test IDs from Admob:
+    // https://developers.google.com/admob/ios/test-ads
+    // https://developers.google.com/admob/android/test-ads
+    final String bannerId = Platform.isAndroid
+        ? 'ca-app-pub-3940256099942544/6300978111'
+        : 'ca-app-pub-3940256099942544/2934735716';
+    final BannerAd bannerAd = BannerAd(
+      adUnitId: bannerId,
+      request: const AdRequest(),
+      size: AdSize.banner,
+      listener: const BannerAdListener(),
+    );
+    bannerAd.load();
+    return Align(
+        alignment: Alignment.bottomCenter,
+        // Use 320x50 Admob standard banner size.
+        child: SizedBox(
+          width: 320,
+          height: 50,
+          child: AdWidget(ad: bannerAd),
+        ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      theme: ThemeData.light(),
+      title: 'Advanced Layout',
+      home: Scaffold(
+        appBar: AppBar(title: const Text('Platform View Bottom Ad Banner')),
+        body: Column(
+          children: <Widget>[
+            Expanded(
+              child: ListView.builder(
+                key: const Key('platform-views-scroll'), // This key is used by the driver test.
+                itemCount: 250,
+                itemBuilder: (BuildContext context, int index) {
+                  return const Card(
+                    elevation: 2,
+                    child: ListTile(
+                      title: Text('Breaking News!'),
+                      subtitle: Text('Huge breaking news! Here is huge and breaking news which is both huge and breaking.'),
+                      leading: FlutterLogo(),
+                    ),
+                  );
+                },
+              ),
+            ),
+            _getBannerWidget(),
+          ]
+        )
+      ),
+    );
+  }
+}

dev/benchmarks/platform_views_layout/test_driver/scroll_perf_bottom_ad_banner_test.dart

@@ -0,0 +1,59 @@
+// 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/flutter_driver.dart';
+import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
+
+void main() {
+  group('scrolling performance test', () {
+    late FlutterDriver driver;
+
+    setUpAll(() async {
+      driver = await FlutterDriver.connect();
+
+      await driver.waitUntilFirstFrameRasterized();
+    });
+
+    tearDownAll(() async {
+      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));
+
+      final Timeline timeline = await driver.traceAction(() async {
+        // Find the scrollable stock list
+        final SerializableFinder list = find.byValueKey(listKey);
+
+        for (int j = 0; j < 5; j += 1) {
+          // 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);
+      await 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_bottom_ad_banner');
+      });
+    }, timeout: Timeout.none);
+  });
+}

dev/benchmarks/platform_views_layout/test_driver/uikit_view_scroll_perf_bottom_ad_banner.dart

@@ -0,0 +1,13 @@
+// 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/widgets.dart';
+import 'package:flutter_driver/driver_extension.dart';
+
+import 'package:platform_views_layout/main_bottom_ad_banner.dart' as app;
+
+void main() {
+  enableFlutterDriverExtension();
+  runApp(const app.PlatformViewApp());
+}

dev/devicelab/bin/tasks/platform_views_scroll_perf_bottom_ad_banner__timeline_summary.dart

@@ -0,0 +1,12 @@
+// 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/devices.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+import 'package:flutter_devicelab/tasks/perf_tests.dart';
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.ios;
+  await task(createUiKitViewScrollPerfBottomAdBannerTest(enableImpeller: true));
+}

dev/devicelab/lib/tasks/perf_tests.dart

@@ -74,6 +74,17 @@ TaskFunction createUiKitViewScrollPerfAdBannersTest({bool? enableImpeller}) {
   ).run;
 }
 
+TaskFunction createUiKitViewScrollPerfBottomAdBannerTest({bool? enableImpeller}) {
+  return PerfTest(
+    '${flutterDirectory.path}/dev/benchmarks/platform_views_layout',
+    'test_driver/uikit_view_scroll_perf_bottom_ad_banner.dart',
+    'platform_views_scroll_perf_bottom_ad_banner',
+    testDriver: 'test_driver/scroll_perf_bottom_ad_banner_test.dart',
+    needsFullTimeline: false,
+    enableImpeller: enableImpeller,
+  ).run;
+}
+
 TaskFunction createUiKitViewScrollPerfNonIntersectingTest({bool? enableImpeller}) {
   return PerfTest(
     '${flutterDirectory.path}/dev/benchmarks/platform_views_layout',