Test that stopped transceivers don't prevent offer/answer

Bug: chromium:1127625
Change-Id: I9ac8b6b90f241460ade299914369405363a36403
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2410407
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Reviewed-by: Philipp Hancke <philipp.hancke@googlemail.com>
Cr-Commit-Position: refs/heads/master@{#807790}

third_party/blink/web_tests/external/wpt/webrtc/RTCRtpTransceiver-stop-expected.txt

@@ -3,5 +3,7 @@ PASS A transceiver added and stopped before the initial offer generation should
 PASS During renegotiation, adding and stopping a transceiver should not trigger a renegotiated offer m-section generation
 FAIL A stopped sendonly transceiver should generate a sendonly m-section in the offer assert_true: The audio m-section should be sendonly expected true got false
 PASS A stopped inactive transceiver should generate an inactive m-section in the offer
+PASS If a track is stopped locally, setting a locally generated answer should still work
+PASS If a track is stopped remotely, setting a locally generated answer should still work
 Harness: the test ran to completion.
 

third_party/blink/web_tests/external/wpt/webrtc/RTCRtpTransceiver-stop.html

@@ -79,4 +79,29 @@ promise_test(async (t)=> {
 
     assert_true(offer.sdp.includes("a=inactive"), "The audio m-section should be inactive");
 }, "A stopped inactive transceiver should generate an inactive m-section in the offer");
+
+promise_test(async (t) => {
+  const pc1 = new RTCPeerConnection();
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  t.add_cleanup(() => pc2.close());
+  pc1.addTransceiver("audio");
+  await exchangeOfferAnswer(pc1, pc2);
+  pc1.getTransceivers()[0].stop();
+  await exchangeOfferAnswer(pc1, pc2);
+  await pc1.setLocalDescription(await pc1.createOffer());
+}, 'If a track is stopped locally, setting a locally generated answer should still work');
+
+promise_test(async (t) => {
+  const pc1 = new RTCPeerConnection();
+  const pc2 = new RTCPeerConnection();
+  t.add_cleanup(() => pc1.close());
+  t.add_cleanup(() => pc2.close());
+  pc1.addTransceiver("audio");
+  await exchangeOfferAnswer(pc1, pc2);
+  pc2.getTransceivers()[0].stop();
+  await exchangeOfferAnswer(pc2, pc1);
+  await pc1.setLocalDescription(await pc1.createOffer());
+}, 'If a track is stopped remotely, setting a locally generated answer should still work');
+
 </script>

third_party/blink/web_tests/virtual/webrtc-wpt-plan-b/external/wpt/webrtc/RTCRtpTransceiver-stop-expected.txt

@@ -3,5 +3,7 @@ FAIL A transceiver added and stopped before the initial offer generation should
 FAIL During renegotiation, adding and stopping a transceiver should not trigger a renegotiated offer m-section generation promise_test: Unhandled rejection with value: object "InvalidStateError: Failed to execute 'addTransceiver' on 'RTCPeerConnection': This operation is only supported in 'unified-plan'."
 FAIL A stopped sendonly transceiver should generate a sendonly m-section in the offer promise_test: Unhandled rejection with value: object "InvalidStateError: Failed to execute 'addTransceiver' on 'RTCPeerConnection': This operation is only supported in 'unified-plan'."
 FAIL A stopped inactive transceiver should generate an inactive m-section in the offer promise_test: Unhandled rejection with value: object "InvalidStateError: Failed to execute 'addTransceiver' on 'RTCPeerConnection': This operation is only supported in 'unified-plan'."
+FAIL If a track is stopped locally, setting a locally generated answer should still work promise_test: Unhandled rejection with value: object "InvalidStateError: Failed to execute 'addTransceiver' on 'RTCPeerConnection': This operation is only supported in 'unified-plan'."
+FAIL If a track is stopped remotely, setting a locally generated answer should still work promise_test: Unhandled rejection with value: object "InvalidStateError: Failed to execute 'addTransceiver' on 'RTCPeerConnection': This operation is only supported in 'unified-plan'."
 Harness: the test ran to completion.