Add SkiaPerfPoint and FlutterEngineMetricPoint

Unit tests that cover their translations are also added.

dev/benchmarks/metrics_center/lib/src/flutter.dart

@@ -0,0 +1,22 @@
+// 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:metrics_center/src/common.dart';
+
+/// Convenient class to capture the benchmarks in the Flutter engine repo.
+class FlutterEngineMetricPoint extends MetricPoint {
+  FlutterEngineMetricPoint(
+    String name,
+    double value,
+    String gitRevision, {
+    Map<String, String> moreTags = const <String, String>{},
+  }) : super(
+          value,
+          <String, String>{
+            kNameKey: name,
+            kGithubRepoKey: kFlutterEngineRepo,
+            kGitRevisionKey: gitRevision,
+          }..addAll(moreTags),
+        );
+}

dev/benchmarks/metrics_center/lib/src/github_helper.dart

@@ -0,0 +1,36 @@
+// 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.
+
+// This file uses Dart 2.12 semantics. This is needed as we can't upgrade
+// the SDK constraint to `>=2.12.0-0` before the deps are ready.
+// @dart=2.12
+
+import 'package:github/github.dart';
+
+/// Singleton class to query some Github info with an in-memory cache.
+class GithubHelper {
+  /// Return the singleton helper.
+  factory GithubHelper() {
+    return _singleton;
+  }
+
+  GithubHelper._internal();
+
+  /// The result is cached in memory so querying the same thing again in the
+  /// same process is fast.
+  Future<DateTime> getCommitDateTime(String githubRepo, String sha) async {
+    final String key = '$githubRepo/commit/$sha';
+    if (_commitDateTimeCache[key] == null) {
+      final RepositoryCommit commit = await _github.repositories
+          .getCommit(RepositorySlug.full(githubRepo), sha);
+      _commitDateTimeCache[key] = commit.commit.committer.date;
+    }
+    return _commitDateTimeCache[key]!;
+  }
+
+  static final GithubHelper _singleton = GithubHelper._internal();
+
+  final GitHub _github = GitHub();
+  final Map<String, DateTime> _commitDateTimeCache = <String, DateTime>{};
+}

dev/benchmarks/metrics_center/lib/src/skiaperf.dart

@@ -0,0 +1,187 @@
+// 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.
+
+// This file uses Dart 2.12 semantics. This is needed as we can't upgrade
+// the SDK constraint to `>=2.12.0-0` before the deps are ready.
+// @dart=2.12
+
+import 'package:metrics_center/src/common.dart';
+
+// Skia Perf Format is a JSON file that looks like:
+
+// {
+//     "gitHash": "fe4a4029a080bc955e9588d05a6cd9eb490845d4",
+//     "key": {
+//         "arch": "x86",
+//         "gpu": "GTX660",
+//         "model": "ShuttleA",
+//         "os": "Ubuntu12"
+//     },
+//     "results": {
+//         "ChunkAlloc_PushPop_640_480": {
+//             "nonrendering": {
+//                 "min_ms": 0.01485466666666667,
+//                 "options": {
+//                     "source_type": "bench"
+//                 }
+//             }
+//         },
+//         "DeferredSurfaceCopy_discardable_640_480": {
+//             "565": {
+//                 "min_ms": 2.215988,
+//                 "options": {
+//                     "source_type": "bench"
+//                 }
+//             },
+//     ...
+
+class SkiaPerfPoint extends MetricPoint {
+  SkiaPerfPoint._(this.githubRepo, this.gitHash, this.testName, this.subResult,
+      double value, this._options, this.jsonUrl)
+      : assert(_options[kGithubRepoKey] == null),
+        assert(_options[kGitRevisionKey] == null),
+        assert(_options[kNameKey] == null),
+        super(
+          value,
+          <String, String>{}
+            ..addAll(_options)
+            ..addAll(<String, String>{
+              kGithubRepoKey: githubRepo,
+              kGitRevisionKey: gitHash,
+              kNameKey: testName,
+              kSubResultKey: subResult,
+            }),
+        ) {
+    assert(tags[kGithubRepoKey] != null);
+    assert(tags[kGitRevisionKey] != null);
+    assert(tags[kNameKey] != null);
+  }
+
+  /// Construct [SkiaPerfPoint] from a well-formed [MetricPoint].
+  ///
+  /// The [MetricPoint] must have [kGithubRepoKey], [kGitRevisionKey],
+  /// [kNameKey] in its tags for this to be successful.
+  ///
+  /// If the [MetricPoint] has a tag 'date', that tag will be removed so Skia
+  /// perf can plot multiple metrics with different date as a single trace.
+  /// Skia perf will use the git revision's date instead of this date tag in
+  /// the time axis.
+  factory SkiaPerfPoint.fromPoint(MetricPoint p) {
+    final String githubRepo = p.tags[kGithubRepoKey]!;
+    final String gitHash = p.tags[kGitRevisionKey]!;
+    final String name = p.tags[kNameKey]!;
+    final String subResult = p.tags[kSubResultKey] ?? kSkiaPerfValueKey;
+
+    final Map<String, String> options = <String, String>{}..addEntries(
+        p.tags.entries.where(
+          (MapEntry<String, dynamic> entry) =>
+              entry.key != kGithubRepoKey &&
+              entry.key != kGitRevisionKey &&
+              entry.key != kNameKey &&
+              entry.key != kSubResultKey &&
+              // https://github.com/google/benchmark automatically generates a
+              // 'date' field. If it's included in options, the Skia perf won't
+              // be able to connect different points in a single trace because
+              // the date is always different.
+              entry.key != 'date',
+        ),
+      );
+
+    return SkiaPerfPoint._(
+        githubRepo, gitHash, name, subResult, p.value, options, null);
+  }
+
+  /// In the format of '<owner>/<name>' such as 'flutter/flutter' or
+  /// 'flutter/engine'.
+  final String githubRepo;
+
+  /// SHA such as 'ad20d368ffa09559754e4b2b5c12951341ca3b2d'
+  final String gitHash;
+
+  /// For Flutter devicelab, this is the task name (e.g.,
+  /// 'flutter_gallery__transition_perf'); for Google benchmark, this is the
+  /// benchmark name (e.g., 'BM_ShellShutdown').
+  ///
+  /// In Skia perf web dashboard, this value can be queried and filtered by
+  /// "test".
+  final String testName;
+
+  /// The name of "subResult" comes from the special treatment of "sub_result"
+  /// in SkiaPerf. If not provided, its value will be set to kSkiaPerfValueKey.
+  ///
+  /// When Google benchmarks are converted to SkiaPerfPoint, this subResult
+  /// could be "cpu_time" or "real_time".
+  ///
+  /// When devicelab benchmarks are converted to SkiaPerfPoint, this subResult
+  /// is often the metric name such as "average_frame_build_time_millis" whereas
+  /// the [testName] is the benchmark or task name such as
+  /// "flutter_gallery__transition_perf".
+  final String subResult;
+
+  /// The url to the Skia perf json file in the Google Cloud Storage bucket.
+  ///
+  /// This can be null if the point has been stored in the bucket yet.
+  final String? jsonUrl;
+
+  Map<String, dynamic> _toSubResultJson() {
+    return <String, dynamic>{
+      subResult: value,
+      kSkiaPerfOptionsKey: _options,
+    };
+  }
+
+  /// Convert a list of SkiaPoints with the same git repo and git revision into
+  /// a single json file in the Skia perf format.
+  ///
+  /// The list must be non-empty.
+  static Map<String, dynamic> toSkiaPerfJson(List<SkiaPerfPoint> points) {
+    assert(points.isNotEmpty);
+    assert(() {
+      for (final SkiaPerfPoint p in points) {
+        if (p.githubRepo != points[0].githubRepo ||
+            p.gitHash != points[0].gitHash) {
+          return false;
+        }
+      }
+      return true;
+    }(), 'All points must have same githubRepo and gitHash');
+
+    final Map<String, dynamic> results = <String, dynamic>{};
+    for (final SkiaPerfPoint p in points) {
+      final Map<String, dynamic> subResultJson = p._toSubResultJson();
+      if (results[p.testName] == null) {
+        results[p.testName] = <String, dynamic>{
+          kSkiaPerfDefaultConfig: subResultJson,
+        };
+      } else {
+        // Flutter currently doesn't support having the same name but different
+        // options/configurations. If this actually happens in the future, we
+        // probably can use different values of config (currently there's only
+        // one kSkiaPerfDefaultConfig) to resolve the conflict.
+        assert(results[p.testName][kSkiaPerfDefaultConfig][kSkiaPerfOptionsKey]
+                .toString() ==
+            subResultJson[kSkiaPerfOptionsKey].toString());
+        assert(
+            results[p.testName][kSkiaPerfDefaultConfig][p.subResult] == null);
+        results[p.testName][kSkiaPerfDefaultConfig][p.subResult] = p.value;
+      }
+    }
+
+    return <String, dynamic>{
+      kSkiaPerfGitHashKey: points[0].gitHash,
+      kSkiaPerfResultsKey: results,
+    };
+  }
+
+  // Equivalent to tags without git repo, git hash, and name because those two
+  // are already stored somewhere else.
+  final Map<String, String> _options;
+}
+
+const String kSkiaPerfGitHashKey = 'gitHash';
+const String kSkiaPerfResultsKey = 'results';
+const String kSkiaPerfValueKey = 'value';
+const String kSkiaPerfOptionsKey = 'options';
+
+const String kSkiaPerfDefaultConfig = 'default';

dev/benchmarks/metrics_center/test/google_benchmark_test.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import 'package:metrics_center/src/common.dart';
 import 'package:metrics_center/google_benchmark.dart';