Bug 1688936 [wpt PR 27336] - webrtc wpt: do not use assert in helper function, a=testonly

Automatic update from web-platform-tests
webrtc wpt: do not use assert in helper function

this spams the testharness log of assertions a test runs

BUG=None

Change-Id: Ib14a7d45f3e18723a667ac292ecb3bdfd2e64ce3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2649933
Reviewed-by: Henrik Boström <hbos@chromium.org>
Reviewed-by: Harald Alvestrand <hta@chromium.org>
Commit-Queue: Philipp Hancke <philipp.hancke@googlemail.com>
Cr-Commit-Position: refs/heads/master@{#852848}

--

wpt-commits: 7ac29511f2edf0203af1911013017f2c6598f035
wpt-pr: 27336

testing/web-platform/tests/webrtc/RTCPeerConnection-helper.js

@@ -242,8 +242,7 @@ async function waitForIceGatheringState(pc, wantedStates) {
 async function listenForSSRCs(t, receiver) {
   while (true) {
     const ssrcs = receiver.getSynchronizationSources();
-    assert_true(Array.isArray(ssrcs));
-    if (ssrcs.length > 0) {
+    if (Array.isArray(ssrcs) && ssrcs.length > 0) {
       return ssrcs;
     }
     await new Promise(r => t.step_timeout(r, 0));