Add regression test for a MediaRecorder::StopRecording crash.

This change adds an additional unit test for the case encountered in
crbug.com/1040339. It's verified to crash if the fix for 1040339 is reverted.

Bug: 1040339
Change-Id: I940aef360589eb917b49e91f6eb84ad4014e0e31
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2003175Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Markus Handell <handellm@google.com>
Cr-Commit-Position: refs/heads/master@{#732456}

third_party/blink/renderer/modules/BUILD.gn

@@ -323,6 +323,7 @@ jumbo_source_set("unit_tests") {
     "mediarecorder/audio_track_recorder_unittest.cc",
     "mediarecorder/fake_encoded_video_frame.h",
     "mediarecorder/media_recorder_handler_unittest.cc",
+    "mediarecorder/media_recorder_unittest.cc",
     "mediarecorder/track_recorder_unittest.cc",
     "mediarecorder/video_track_recorder_unittest.cc",
     "mediasession/media_session_test.cc",

third_party/blink/renderer/modules/mediarecorder/media_recorder_unittest.cc

+// Copyright 2019 The Chromium 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 "third_party/blink/renderer/modules/mediarecorder/media_recorder.h"
+
+#include <memory>
+
+#include "testing/gmock/include/gmock/gmock.h"
+#include "third_party/blink/public/web/modules/mediastream/media_stream_video_track.h"
+#include "third_party/blink/public/web/web_heap.h"
+#include "third_party/blink/renderer/bindings/core/v8/v8_binding_for_testing.h"
+#include "third_party/blink/renderer/modules/mediastream/mock_media_stream_registry.h"
+#include "third_party/blink/renderer/modules/mediastream/mock_media_stream_video_source.h"
+#include "third_party/blink/renderer/platform/mediastream/media_stream_audio_source.h"
+#include "third_party/blink/renderer/platform/testing/io_task_runner_testing_platform_support.h"
+
+namespace blink {
+namespace {
+
+MediaStream* CreateMediaStream(V8TestingScope* scope) {
+  WebMediaStreamSource blink_source;
+  blink_source.Initialize("video source id", WebMediaStreamSource::kTypeVideo,
+                          "video source name", false /* remote */);
+  auto native_source = std::make_unique<MockMediaStreamVideoSource>();
+  MockMediaStreamVideoSource* native_source_ptr = native_source.get();
+  blink_source.SetPlatformSource(std::move(native_source));
+  auto* component = MakeGarbageCollected<MediaStreamComponent>(blink_source);
+  component->SetPlatformTrack(std::make_unique<MediaStreamVideoTrack>(
+      native_source_ptr, MediaStreamVideoSource::ConstraintsOnceCallback(),
+      true /* enabled */));
+  auto* track = MakeGarbageCollected<MediaStreamTrack>(
+      scope->GetExecutionContext(), component);
+  return MediaStream::Create(scope->GetExecutionContext(),
+                             MediaStreamTrackVector{track});
+}
+}  // namespace
+
+// This is a regression test for crbug.com/1999203
+TEST(MediaRecorderTest,
+     AcceptsAllTracksEndedEventWhenExecutionContextDestroyed) {
+  ScopedTestingPlatformSupport<IOTaskRunnerTestingPlatformSupport> platform;
+  {
+    V8TestingScope scope;
+    MediaStream* stream = CreateMediaStream(&scope);
+    MediaRecorder* recorder = MakeGarbageCollected<MediaRecorder>(
+        scope.GetExecutionContext(), stream, MediaRecorderOptions::Create(),
+        scope.GetExceptionState());
+    recorder->start(scope.GetExceptionState());
+    for (const auto& track : stream->getTracks())
+      track->Component()->GetPlatformTrack()->Stop();
+  }
+  platform->RunUntilIdle();
+  WebHeap::CollectAllGarbageForTesting();
+}
+
+}  // namespace blink