Reduce flakiness in EndToEnd probing tests.

webrtc/test/call_test.cc

Index: webrtc/test/call_test.cc
diff --git a/webrtc/test/call_test.cc b/webrtc/test/call_test.cc
index 3a13eeef862a802e17a3ba7432b809e433024bba..61fbe37a16d9ead934ea7691c8cdf28d8ed1eb66 100644
--- a/webrtc/test/call_test.cc
+++ b/webrtc/test/call_test.cc
@@ -232,8 +232,8 @@ void CallTest::CreateSendConfig(size_t num_video_streams,
 }
 
 void CallTest::CreateMatchingReceiveConfigs(Transport* rtcp_send_transport) {
-  RTC_DCHECK(video_receive_configs_.empty());
-  RTC_DCHECK(allocated_decoders_.empty());
+  video_receive_configs_.clear();
+  allocated_decoders_.clear();
   if (num_video_streams_ > 0) {
     RTC_DCHECK(!video_send_config_.rtp.ssrcs.empty());
     VideoReceiveStream::Config video_config(rtcp_send_transport);