Reland: Fix race / crash in OnNetworkRouteChanged().

webrtc/modules/congestion_controller/delay_based_bwe_unittest_helper.h

Index: webrtc/modules/congestion_controller/delay_based_bwe_unittest_helper.h
diff --git a/webrtc/modules/congestion_controller/delay_based_bwe_unittest_helper.h b/webrtc/modules/congestion_controller/delay_based_bwe_unittest_helper.h
index f97cd5272d8589b5b26bd25699c74a5cf4edbd65..add9fb32774f9552501ea7f418a3153566c79538 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe_unittest_helper.h
+++ b/webrtc/modules/congestion_controller/delay_based_bwe_unittest_helper.h
@@ -19,6 +19,7 @@
 
 #include "webrtc/test/gtest.h"
 #include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/congestion_controller/delay_based_bwe.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
 #include "webrtc/system_wrappers/include/clock.h"
 
@@ -160,8 +161,8 @@ class DelayBasedBweTest : public ::testing::Test {
   static const uint32_t kDefaultSsrc;
 
   SimulatedClock clock_;  // Time at the receiver.
-  std::unique_ptr<test::TestBitrateObserver> bitrate_observer_;
-  std::unique_ptr<RemoteBitrateEstimator> bitrate_estimator_;
+  test::TestBitrateObserver bitrate_observer_;
+  DelayBasedBwe bitrate_estimator_;
   std::unique_ptr<test::StreamGenerator> stream_generator_;
   int64_t arrival_time_offset_ms_;