Test that DTMFSender rejects properly after close

This verifies that the sender throws the right error
when called after the connection closing.

Bug: chromium:822799
Change-Id: Id3ab4ddc65b1510526fa49b7bfe3f9f95a7f2d65
Reviewed-on: https://chromium-review.googlesource.com/968927Reviewed-by: Henrik Boström <hbos@chromium.org>
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544804}

third_party/WebKit/LayoutTests/external/wpt/webrtc/RTCDTMFSender-insertDTMF.https-expected.txt

@@ -5,5 +5,6 @@ FAIL insertDTMF() should throw InvalidStateError if transceiver is stopped pc.ad
 FAIL insertDTMF() should throw InvalidStateError if transceiver.currentDirection is recvonly pc.addTransceiver is not a function
 FAIL insertDTMF() should throw InvalidStateError if transceiver.currentDirection is inactive pc.addTransceiver is not a function
 PASS insertDTMF() should set toneBuffer to provided tones normalized, with old tones overridden
+PASS insertDTMF() after remove and close should reject
 Harness: the test ran to completion.
 

third_party/WebKit/LayoutTests/external/wpt/webrtc/RTCDTMFSender-insertDTMF.https.html

@@ -162,4 +162,22 @@
     });
   }, 'insertDTMF() should set toneBuffer to provided tones normalized, with old tones overridden');
 
+  promise_test(t => {
+    let dtmfSender;
+    let sender;
+    let pc = new RTCPeerConnection();
+    return getTrackFromUserMedia('audio')
+      .then(([track, mediaStream]) => {
+        sender = pc.addTrack(track, mediaStream);
+        return pc.createOffer();
+      }).then(offer => {
+        pc.setLocalDescription(offer);
+        dtmfSender = sender.dtmf;
+        pc.removeTrack(sender);
+        pc.close();
+        assert_throws('InvalidStateError', () =>
+                      dtmfSender.insertDTMF('123'));
+      });
+  }, 'insertDTMF() after remove and close should reject');
+
 </script>