Add PeerConnectionObserver::OnRemoveTrack callback.

webrtc/pc/peerconnectioninterface_unittest.cc

Index: webrtc/pc/peerconnectioninterface_unittest.cc
diff --git a/webrtc/pc/peerconnectioninterface_unittest.cc b/webrtc/pc/peerconnectioninterface_unittest.cc
index 1a26a4352277fa5aa616f80d5725f82707bcce1b..ad1f95b4c1b9194355d518cef66fbce2ea4e2e17 100644
--- a/webrtc/pc/peerconnectioninterface_unittest.cc
+++ b/webrtc/pc/peerconnectioninterface_unittest.cc
@@ -606,6 +606,15 @@ class MockPeerConnectionObserver : public PeerConnectionObserver {
     last_added_track_label_ = receiver->id();
   }
 
+  void OnRemoveTrack(
+      rtc::scoped_refptr<RtpReceiverInterface> receiver,
+      const std::vector<rtc::scoped_refptr<MediaStreamInterface>> &
+          streams) override {
+    EXPECT_TRUE(receiver != nullptr);
+    num_removed_tracks_++;
+    last_removed_track_label_ = receiver->id();
+  }
+
   // Returns the label of the last added stream.
   // Empty string if no stream have been added.
   std::string GetLastAddedStreamLabel() {
@@ -629,6 +638,8 @@ class MockPeerConnectionObserver : public PeerConnectionObserver {
   bool callback_triggered_ = false;
   int num_added_tracks_ = 0;
   std::string last_added_track_label_;
+  int num_removed_tracks_ = 0;
+  std::string last_removed_track_label_;
 
  private:
   rtc::scoped_refptr<MediaStreamInterface> last_added_stream_;
@@ -864,9 +875,10 @@ class PeerConnectionInterfaceTest : public testing::Test {
     observer_.renegotiation_needed_ = false;
   }
 
-  void AddAudioVideoStream(const std::string& stream_label,
-                           const std::string& audio_track_label,
-                           const std::string& video_track_label) {
+  rtc::scoped_refptr<MediaStreamInterface> AddAudioVideoStream(
+      const std::string& stream_label,
+      const std::string& audio_track_label,
+      const std::string& video_track_label) {
     // Create a local stream.
     rtc::scoped_refptr<MediaStreamInterface> stream(
         pc_factory_->CreateLocalMediaStream(stream_label));
@@ -883,6 +895,7 @@ class PeerConnectionInterfaceTest : public testing::Test {
     EXPECT_TRUE(pc_->AddStream(stream));
     EXPECT_TRUE_WAIT(observer_.renegotiation_needed_, kTimeout);
     observer_.renegotiation_needed_ = false;
+    return stream;
   }
 
   bool DoCreateOfferAnswer(std::unique_ptr<SessionDescriptionInterface>* desc,
@@ -3770,3 +3783,21 @@ TEST_F(PeerConnectionInterfaceTest, MediaStreamAddTrackRemoveTrackRenegotiate) {
   EXPECT_TRUE_WAIT(observer_.renegotiation_needed_, kTimeout);
   observer_.renegotiation_needed_ = false;
 }
+
+// This tests that PeerConnectionObserver::OnRemoveTrack is correctly called.
+TEST_F(PeerConnectionInterfaceTest, OnRemoveTrackCallback) {
+  CreatePeerConnectionWithoutDtls();
+  auto stream = AddAudioVideoStream(
+    kStreamLabel1, "audio_label", "video_label");
+  CreateOfferReceiveAnswer();
+
+  auto audio_track = stream->GetAudioTracks()[0];
+  EXPECT_TRUE(stream->RemoveTrack(audio_track));
+  EXPECT_TRUE_WAIT(observer_.renegotiation_needed_, kTimeout);
+  observer_.renegotiation_needed_ = false;
+
+  CreateOfferReceiveAnswer();
+
+  EXPECT_EQ(observer_.num_removed_tracks_, 1u);
+  EXPECT_EQ(observer_.last_removed_track_label_, audio_track->id());
+}