Make sure RTCP is sent in tests when receiving packets even if REMB is delayed.

webrtc/video/rampup_tests.cc

Index: webrtc/video/rampup_tests.cc
diff --git a/webrtc/video/rampup_tests.cc b/webrtc/video/rampup_tests.cc
index c35991f974459a9654f832214c02963f1e0f080b..c3c97878e295f05b4a23ff4bf7f5c968889c47ad 100644
--- a/webrtc/video/rampup_tests.cc
+++ b/webrtc/video/rampup_tests.cc
@@ -124,6 +124,7 @@ bool StreamObserver::SendRtp(const uint8_t* packet, size_t length) {
       clock_->TimeInMilliseconds(), length - header.headerLength, header, true);
   if (remote_bitrate_estimator_->TimeUntilNextProcess() <= 0) {
     remote_bitrate_estimator_->Process();
+    rtp_rtcp_->Process();
   }
   total_sent_ += length;
   padding_sent_ += header.paddingLength;