Adds a test for an one-way media PeerConnection.

webrtc/api/peerconnection_unittest.cc

Index: webrtc/api/peerconnection_unittest.cc
diff --git a/webrtc/api/peerconnection_unittest.cc b/webrtc/api/peerconnection_unittest.cc
index a43d075d57416231cbf5765baba5f516763d3b0a..a7d490c0a2563f2dd9aa18ddcbeb374acd47f1da 100644
--- a/webrtc/api/peerconnection_unittest.cc
+++ b/webrtc/api/peerconnection_unittest.cc
@@ -415,7 +415,7 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
     return data_observer_.get();
   }
 
-  webrtc::PeerConnectionInterface* pc() { return peer_connection_.get(); }
+  webrtc::PeerConnectionInterface* pc() const { return peer_connection_.get(); }
 
   void StopVideoCapturers() {
     for (std::vector<cricket::VideoCapturer*>::iterator it =
@@ -426,6 +426,10 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
   }
 
   bool AudioFramesReceivedCheck(int number_of_frames) const {
+    // Only check frames if the incoming stream exists.
+    if (remote_streams()->count() == 0) {

[perkj_webrtc, 2016/03/08 23:07:50]

can you please refactor LocalP2PTest instead? There is already a check for
can_receive... to fix this this. But it checks both the sender and the receiver
as one unit instead of separate. ie number_of_frames should be 0 if you dont
expect a frame.

[hta-webrtc, 2016/03/09 04:09:53]

I'd like not to, because I've got another CL in flight that significantly
restructures this whole piece of infrastructure (constraint removal). Would a
TODO be sufficient at this time?

The check for can_receive.... was wrong. It did not work for one-way media - in
the one-way media case, we're perfectly happy to receive, there just isn't
anyone sending.

[hta-webrtc, 2016/03/09 09:40:17]

Only took an hour to restructure the counting. Looks better?

+      return true;
+    }
     return number_of_frames <= fake_audio_capture_module_->frames_received();
   }
 
@@ -434,6 +438,10 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
   }
 
   bool VideoFramesReceivedCheck(int number_of_frames) {
+    // Only check frames if the incoming stream exists.
+    if (remote_streams()->count() == 0) {
+      return true;
+    }
     if (video_decoder_factory_enabled_) {
       const std::vector<FakeWebRtcVideoDecoder*>& decoders
           = fake_video_decoder_factory_->decoders();
@@ -660,7 +668,7 @@ class PeerConnectionTestClient : public webrtc::PeerConnectionObserver,
     return pc()->remote_streams()->count();
   }
 
-  StreamCollectionInterface* remote_streams() {
+  StreamCollectionInterface* remote_streams() const {
     if (!pc()) {
       ADD_FAILURE();
       return nullptr;
@@ -1213,6 +1221,14 @@ TEST_F(P2PTestConductor, LocalP2PTestDtls) {
   SetupAndVerifyDtlsCall();
 }
 
+// This test sets up an one-way call, with media only from initiator to
+// responder.
+TEST_F(P2PTestConductor, OneWayMediaCall) {
+  ASSERT_TRUE(CreateTestClients());
+  receiving_client()->set_auto_add_stream(false);
+  LocalP2PTest();
+}
+
 // This test sets up a audio call initially and then upgrades to audio/video,
 // using DTLS.
 TEST_F(P2PTestConductor, LocalP2PTestDtlsRenegotiate) {