[web] Add path construction benchmark (#57016)

* Add path construction benchmark

* Fix analyzer warnings

* Split file into test+generated code. Add comment

* Add license to new file

* remove unused import

dev/benchmarks/macrobenchmarks/lib/src/web/bench_paths.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/src/web/recorder.dart';
+import 'package:macrobenchmarks/src/web/bench_paths_recording.dart'
+    as recording;
+
+/// Measure the performance of path construction.
+///
+/// This benchmarks was generated by running flutter gallery and recording
+/// path calls.
+class BenchPathRecording extends RawRecorder {
+  BenchPathRecording() : super(name: benchmarkName);
+
+  static const String benchmarkName = 'bench_path_recording';
+
+  @override
+  Future<void> setUpAll() async {
+  }
+
+  @override
+  void body(Profile profile) {
+    profile.record('recordPathConstruction', () {
+      for (int i = 1; i <= 10; i++) {
+        recording.createPaths();
+      }
+    }, reported: true);
+  }
+}

dev/benchmarks/macrobenchmarks/lib/web_benchmarks.dart

@@ -15,6 +15,7 @@ import 'src/web/bench_card_infinite_scroll.dart';
 import 'src/web/bench_clipped_out_pictures.dart';
 import 'src/web/bench_draw_rect.dart';
 import 'src/web/bench_dynamic_clip_on_static_picture.dart';
+import 'src/web/bench_paths.dart';
 import 'src/web/bench_picture_recording.dart';
 import 'src/web/bench_simple_lazy_text_scroll.dart';
 import 'src/web/bench_text_out_of_picture_bounds.dart';
@@ -32,6 +33,7 @@ final Map<String, RecorderFactory> benchmarks = <String, RecorderFactory>{
   BenchCardInfiniteScroll.benchmarkName: () => BenchCardInfiniteScroll(),
   BenchClippedOutPictures.benchmarkName: () => BenchClippedOutPictures(),
   BenchDrawRect.benchmarkName: () => BenchDrawRect(),
+  BenchPathRecording.benchmarkName: () => BenchPathRecording(),
   BenchTextOutOfPictureBounds.benchmarkName: () => BenchTextOutOfPictureBounds(),
   BenchSimpleLazyTextScroll.benchmarkName: () => BenchSimpleLazyTextScroll(),
   BenchBuildMaterialCheckbox.benchmarkName: () => BenchBuildMaterialCheckbox(),