Fix races in MediaStream video constraints tests.

content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc

Index: content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc
diff --git a/content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc b/content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc
index a5a9874f3df89bfac0cfa0da7eb841956405849f..9f2d82ad589d716b06758faea3030bd3f2f0fc0a 100644
--- a/content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc
+++ b/content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc
@@ -18,7 +18,10 @@ namespace {
 
 class MediaStreamVideoWebRtcSinkTest : public ::testing::Test {
  public:
-  MediaStreamVideoWebRtcSinkTest() {}
+  MediaStreamVideoWebRtcSinkTest() {
+    scoped_feature_list_.InitAndDisableFeature(
+        features::kMediaStreamOldVideoConstraints);
+  }
 
   void SetVideoTrack() {
     registry_.Init("stream URL");
@@ -61,27 +64,10 @@ class MediaStreamVideoWebRtcSinkTest : public ::testing::Test {
   // and Sources in |registry_| into believing they are on the right threads.
   base::MessageLoopForUI message_loop_;
   const ChildProcess child_process_;
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
-// TODO(guidou): Remove this test. http://crbug.com/706408
-TEST_F(MediaStreamVideoWebRtcSinkTest,
-       NoiseReductionDefaultsToNotSetOldConstraints) {
-  base::test::ScopedFeatureList scoped_feature_list;
-  scoped_feature_list.InitAndEnableFeature(
-      features::kMediaStreamOldVideoConstraints);
-  blink::WebMediaConstraints constraints;
-  constraints.initialize();
-  SetVideoTrack(constraints);
-  MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
-  EXPECT_TRUE(my_sink.webrtc_video_track());
-  EXPECT_FALSE(my_sink.SourceNeedsDenoisingForTesting());
-}
-
-// TODO(guidou): Remove this test. http://crbug.com/706408
 TEST_F(MediaStreamVideoWebRtcSinkTest, NoiseReductionDefaultsToNotSet) {
-  base::test::ScopedFeatureList scoped_feature_list;
-  scoped_feature_list.InitAndDisableFeature(
-      features::kMediaStreamOldVideoConstraints);
   SetVideoTrack();
   MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
   EXPECT_TRUE(my_sink.webrtc_video_track());
@@ -89,25 +75,80 @@ TEST_F(MediaStreamVideoWebRtcSinkTest, NoiseReductionDefaultsToNotSet) {
 }
 
 // TODO(guidou): Remove this test. http://crbug.com/706408
-TEST_F(MediaStreamVideoWebRtcSinkTest,
-       NoiseReductionConstraintPassThroughOldConstraints) {
-  base::test::ScopedFeatureList scoped_feature_list;
-  scoped_feature_list.InitAndEnableFeature(
-      features::kMediaStreamOldVideoConstraints);
-  MockConstraintFactory factory;
-  factory.basic().googNoiseReduction.setExact(true);
-  SetVideoTrack(factory.CreateWebMediaConstraints());
+TEST_F(MediaStreamVideoWebRtcSinkTest, NoiseReductionConstraintPassThrough) {
+  SetVideoTrack(base::Optional<bool>(true));
   MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
   EXPECT_TRUE(my_sink.SourceNeedsDenoisingForTesting());
   EXPECT_TRUE(*(my_sink.SourceNeedsDenoisingForTesting()));
 }
 
 // TODO(guidou): Remove this test. http://crbug.com/706408
-TEST_F(MediaStreamVideoWebRtcSinkTest, NoiseReductionConstraintPassThrough) {
-  base::test::ScopedFeatureList scoped_feature_list;
-  scoped_feature_list.InitAndDisableFeature(
-      features::kMediaStreamOldVideoConstraints);
-  SetVideoTrack(base::Optional<bool>(true));
+class MediaStreamVideoWebRtcSinkOldConstraintsTest : public ::testing::Test {
+ public:
+  MediaStreamVideoWebRtcSinkOldConstraintsTest() {
+    scoped_feature_list_.InitAndEnableFeature(
+        features::kMediaStreamOldVideoConstraints);
+  }
+
+  void SetVideoTrack() {
+    registry_.Init("stream URL");
+    registry_.AddVideoTrack("test video track");
+    blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
+    registry_.test_stream().videoTracks(video_tracks);
+    track_ = video_tracks[0];
+    // TODO(hta): Verify that track_ is valid. When constraints produce
+    // no valid format, using the track will cause a crash.
+  }
+
+  void SetVideoTrack(blink::WebMediaConstraints constraints) {
+    registry_.Init("stream URL");
+    registry_.AddVideoTrack("test video track", constraints);
+    blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
+    registry_.test_stream().videoTracks(video_tracks);
+    track_ = video_tracks[0];
+    // TODO(hta): Verify that track_ is valid. When constraints produce
+    // no valid format, using the track will cause a crash.
+  }
+
+  void SetVideoTrack(const base::Optional<bool>& noise_reduction) {
+    registry_.Init("stream URL");
+    registry_.AddVideoTrack("test video track", VideoTrackAdapterSettings(),
+                            noise_reduction, false, 0.0);
+    blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
+    registry_.test_stream().videoTracks(video_tracks);
+    track_ = video_tracks[0];
+    // TODO(hta): Verify that track_ is valid. When constraints produce
+    // no valid format, using the track will cause a crash.
+  }
+
+ protected:
+  blink::WebMediaStreamTrack track_;
+  MockPeerConnectionDependencyFactory dependency_factory_;
+
+ private:
+  MockMediaStreamRegistry registry_;
+  // A ChildProcess and a MessageLoopForUI are both needed to fool the Tracks
+  // and Sources in |registry_| into believing they are on the right threads.
+  base::MessageLoopForUI message_loop_;
+  const ChildProcess child_process_;
+  base::test::ScopedFeatureList scoped_feature_list_;
+};
+
+TEST_F(MediaStreamVideoWebRtcSinkOldConstraintsTest,
+       NoiseReductionDefaultsToNotSet) {
+  blink::WebMediaConstraints constraints;
+  constraints.initialize();
+  SetVideoTrack(constraints);
+  MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
+  EXPECT_TRUE(my_sink.webrtc_video_track());
+  EXPECT_FALSE(my_sink.SourceNeedsDenoisingForTesting());
+}
+
+TEST_F(MediaStreamVideoWebRtcSinkOldConstraintsTest,
+       NoiseReductionConstraintPassThrough) {
+  MockConstraintFactory factory;
+  factory.basic().googNoiseReduction.setExact(true);
+  SetVideoTrack(factory.CreateWebMediaConstraints());
   MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
   EXPECT_TRUE(my_sink.SourceNeedsDenoisingForTesting());
   EXPECT_TRUE(*(my_sink.SourceNeedsDenoisingForTesting()));