[Impeller] measure GPU memory usage. (#144575)

Framework side to https://github.com/flutter/engine/pull/51187

Part of https://github.com/flutter/flutter/issues/144617

dev/devicelab/lib/tasks/perf_tests.dart

@@ -1451,10 +1451,16 @@ class PerfTest {
           if (data['120hz_frame_percentage'] != null) '120hz_frame_percentage',
           if (data['illegal_refresh_rate_frame_count'] != null) 'illegal_refresh_rate_frame_count',
           if (recordGPU) ...<String>[
+            // GPU Frame Time.
             if (data['average_gpu_frame_time'] != null) 'average_gpu_frame_time',
             if (data['90th_percentile_gpu_frame_time'] != null) '90th_percentile_gpu_frame_time',
             if (data['99th_percentile_gpu_frame_time'] != null) '99th_percentile_gpu_frame_time',
             if (data['worst_gpu_frame_time'] != null) 'worst_gpu_frame_time',
+            // GPU Memory.
+            if (data['average_gpu_memory_mb'] != null) 'average_gpu_memory_mb',
+            if (data['90th_percentile_gpu_memory_mb'] != null) '90th_percentile_gpu_memory_mb',
+            if (data['99th_percentile_gpu_memory_mb'] != null) '99th_percentile_gpu_memory_mb',
+            if (data['worst_gpu_memory_mb'] != null) 'worst_gpu_memory_mb',
           ]
         ],
       );

packages/flutter_driver/lib/src/driver/memory_summarizer.dart

@@ -0,0 +1,62 @@
+// 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 'percentile_utils.dart';
+import 'timeline.dart';
+
+/// Summarizes GPU/Device Memory allocations performed by Impeller.
+class GPUMemorySumarizer {
+  /// Creates a RasterCacheSummarizer given the timeline events.
+  GPUMemorySumarizer(List<TimelineEvent> gpuEvents) {
+    for (final TimelineEvent event in gpuEvents) {
+      final Object? value = event.arguments!['MemoryBudgetUsageMB'];
+      if (value is String) {
+        final double? parsedValue = double.tryParse(value);
+        if (parsedValue != null) {
+          _memoryMB.add(parsedValue);
+        }
+      }
+    }
+  }
+
+  /// Whether or not this event is a GPU allocation event.
+  static const Set<String> kMemoryEvents = <String>{'AllocatorVK'};
+
+  final List<double> _memoryMB = <double>[];
+
+  /// Computes the average GPU memory allocated.
+  double computeAverageMemoryUsage() => _computeAverage(_memoryMB);
+
+  /// The [percentile]-th percentile GPU memory allocated.
+  double computePercentileMemoryUsage(double percentile) {
+    if (_memoryMB.isEmpty) {
+      return 0;
+    }
+    return findPercentile(_memoryMB, percentile);
+  }
+
+  /// Compute the worst allocation quantity recorded.
+  double computeWorstMemoryUsage() => _computeWorst(_memoryMB);
+
+  static double _computeAverage(List<double> values) {
+    if (values.isEmpty) {
+      return 0;
+    }
+
+    double total = 0;
+    for (final double data in values) {
+      total += data;
+    }
+    return total / values.length;
+  }
+
+  static double _computeWorst(List<double> values) {
+    if (values.isEmpty) {
+      return 0;
+    }
+
+    values.sort();
+    return values.last;
+  }
+}

packages/flutter_driver/lib/src/driver/timeline_summary.dart

@@ -12,6 +12,7 @@ import 'common.dart';
 import 'frame_request_pending_latency_summarizer.dart';
 import 'gc_summarizer.dart';
 import 'gpu_sumarizer.dart';
+import 'memory_summarizer.dart';
 import 'percentile_utils.dart';
 import 'profiling_summarizer.dart';
 import 'raster_cache_summarizer.dart';
@@ -277,6 +278,7 @@ class TimelineSummary {
     final RefreshRateSummary refreshRateSummary = RefreshRateSummary(vsyncEvents: _extractNamedEvents(kUIThreadVsyncProcessEvent));
     final FrameRequestPendingLatencySummarizer frameRequestPendingLatencySummarizer = _frameRequestPendingLatencySummarizer();
     final GpuSumarizer gpuSummarizer = _gpuSumarizer();
+    final GPUMemorySumarizer memorySumarizer = _memorySummarizer();
 
     final Map<String, dynamic> timelineSummary = <String, dynamic>{
       'average_frame_build_time_millis': computeAverageFrameBuildTimeMillis(),
@@ -342,6 +344,10 @@ class TimelineSummary {
       '90th_percentile_gpu_frame_time': gpuSummarizer.computePercentileGPUTime(90.0),
       '99th_percentile_gpu_frame_time': gpuSummarizer.computePercentileGPUTime(99.0),
       'worst_gpu_frame_time': gpuSummarizer.computeWorstGPUTime(),
+      'average_gpu_memory_mb': memorySumarizer.computeAverageMemoryUsage(),
+      '90th_percentile_gpu_memory_mb': memorySumarizer.computePercentileMemoryUsage(90.0),
+      '99th_percentile_gpu_memory_mb': memorySumarizer.computePercentileMemoryUsage(99.0),
+      'worst_gpu_memory_mb': memorySumarizer.computeWorstMemoryUsage(),
     };
 
     timelineSummary.addAll(profilingSummary);
@@ -501,4 +507,6 @@ class TimelineSummary {
   GCSummarizer _gcSummarizer() => GCSummarizer.fromEvents(_extractEventsWithNames(kGCRootEvents));
 
   GpuSumarizer _gpuSumarizer() => GpuSumarizer(_extractEventsWithNames(GpuSumarizer.kGpuEvents));
+
+  GPUMemorySumarizer _memorySummarizer() => GPUMemorySumarizer(_extractEventsWithNames(GPUMemorySumarizer.kMemoryEvents));
 }

packages/flutter_driver/test/src/gpu_memory_summarizer_test.dart

@@ -0,0 +1,31 @@
+// 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:flutter_driver/src/driver/memory_summarizer.dart';
+
+import '../common.dart';
+
+TimelineEvent newGPUTraceEvent(double ms) => TimelineEvent(<String, dynamic>{
+  'name': 'AllocatorVK',
+  'ph': 'b',
+  'args': <String, String>{
+    'MemoryBudgetUsageMB': ms.toString()
+  },
+});
+
+void main() {
+  test('Can process GPU memory usage times.', () {
+    final GPUMemorySumarizer summarizer = GPUMemorySumarizer(<TimelineEvent>[
+      newGPUTraceEvent(1024),
+      newGPUTraceEvent(1024),
+      newGPUTraceEvent(512),
+      newGPUTraceEvent(2048),
+    ]);
+
+    expect(summarizer.computeAverageMemoryUsage(), closeTo(1152, 0.1));
+    expect(summarizer.computePercentileMemoryUsage(50.0), closeTo(1024, 0.1));
+    expect(summarizer.computeWorstMemoryUsage(), 2048);
+  });
+}

packages/flutter_driver/test/src/real_tests/timeline_summary_test.dart

@@ -532,6 +532,10 @@ void main() {
             '90th_percentile_gpu_frame_time': 0,
             '99th_percentile_gpu_frame_time': 0,
             'worst_gpu_frame_time': 0,
+            'average_gpu_memory_mb': 0,
+            '90th_percentile_gpu_memory_mb': 0,
+            '99th_percentile_gpu_memory_mb': 0,
+            'worst_gpu_memory_mb': 0,
           },
         );
       });
@@ -667,6 +671,10 @@ void main() {
           '90th_percentile_gpu_frame_time': 0,
           '99th_percentile_gpu_frame_time': 0,
           'worst_gpu_frame_time': 0,
+          'average_gpu_memory_mb': 0,
+          '90th_percentile_gpu_memory_mb': 0,
+          '99th_percentile_gpu_memory_mb': 0,
+          'worst_gpu_memory_mb': 0,
         });
       });
     });