Perform probing on network route change.

webrtc/modules/congestion_controller/congestion_controller_unittest.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 41 matching lines @@
     controller_.reset(new CongestionController(
         &clock_, &observer_, &remote_bitrate_observer_, &event_log_,
         &packet_router_, std::move(pacer)));
     bandwidth_observer_.reset(
         controller_->GetBitrateController()->CreateRtcpBandwidthObserver());
 
     // Set the initial bitrate estimate and expect the |observer| and |pacer_|
     // to be updated.
     EXPECT_CALL(observer_, OnNetworkChanged(kInitialBitrateBps, _, _, _));
     EXPECT_CALL(*pacer_, SetEstimatedBitrate(kInitialBitrateBps));
+    EXPECT_CALL(*pacer_, CreateProbeCluster(kInitialBitrateBps * 3));
+    EXPECT_CALL(*pacer_, CreateProbeCluster(kInitialBitrateBps * 5));
     controller_->SetBweBitrates(0, kInitialBitrateBps, 5 * kInitialBitrateBps);
   }
 
   SimulatedClock clock_;
   StrictMock<MockCongestionObserver> observer_;
   NiceMock<MockPacedSender>* pacer_;
   NiceMock<MockRemoteBitrateObserver> remote_bitrate_observer_;
   NiceMock<MockRtcEventLog> event_log_;
   std::unique_ptr<RtcpBandwidthObserver> bandwidth_observer_;
   PacketRouter packet_router_;
@@ skipping 64 matching lines @@
 
   EXPECT_CALL(observer_, OnNetworkChanged(kInitialBitrateBps, _, _, _));
   controller_->SignalNetworkState(kNetworkUp);
 
   EXPECT_CALL(observer_, OnNetworkChanged(0, _, _, _));
   controller_->SignalNetworkState(kNetworkDown);
 }
 
 TEST_F(CongestionControllerTest, ResetBweAndBitrates) {
   int new_bitrate = 200000;
+  testing::Mock::VerifyAndClearExpectations(pacer_);
   EXPECT_CALL(observer_, OnNetworkChanged(new_bitrate, _, _, _));
   EXPECT_CALL(*pacer_, SetEstimatedBitrate(new_bitrate));
   controller_->ResetBweAndBitrates(new_bitrate, -1, -1);
 
   // If the bitrate is reset to -1, the new starting bitrate will be
   // the minimum default bitrate kMinBitrateBps.
   EXPECT_CALL(
       observer_,
       OnNetworkChanged(congestion_controller::GetMinBitrateBps(), _, _, _));
   EXPECT_CALL(*pacer_,
@@ skipping 77 matching lines @@
   for (int i = 0; i < 10; ++i) {
     clock_.AdvanceTimeMilliseconds((1000 * payload_size) / kInitialBitrateBps);
     int64_t now_ms = clock_.TimeInMilliseconds();
     header.extension.absoluteSendTime = AbsSendTime(now_ms, 1000);
     controller_->OnReceivedPacket(now_ms, payload_size, header);
   }
 
   ASSERT_EQ(1u, ssrcs.size());
   EXPECT_EQ(header.ssrc, ssrcs[0]);
 }
+
+TEST_F(CongestionControllerTest, ProbeOnBweReset) {
+  testing::Mock::VerifyAndClearExpectations(pacer_);
+  EXPECT_CALL(*pacer_, CreateProbeCluster(kInitialBitrateBps * 6));
+  EXPECT_CALL(*pacer_, CreateProbeCluster(kInitialBitrateBps * 12));
+  EXPECT_CALL(observer_, OnNetworkChanged(kInitialBitrateBps * 2, _, _, _));
+  controller_->ResetBweAndBitrates(2 * kInitialBitrateBps, 0,
+                                   20 * kInitialBitrateBps);
+}
+
 }  // namespace test
 }  // namespace webrtc