Fix race / crash in OnNetworkRouteChanged().

webrtc/video/video_send_stream_tests.cc

Index: webrtc/video/video_send_stream_tests.cc
diff --git a/webrtc/video/video_send_stream_tests.cc b/webrtc/video/video_send_stream_tests.cc
index a36be32d32834679aa9c12bb58327a6c4b8dae02..79b3e0483e243c171eba8c30321e8db4fbac60c0 100644
--- a/webrtc/video/video_send_stream_tests.cc
+++ b/webrtc/video/video_send_stream_tests.cc
@@ -1135,20 +1135,44 @@ TEST_F(VideoSendStreamTest, MinTransmitBitrateRespectsRemb) {
   RunBaseTest(&test);
 }
 
-TEST_F(VideoSendStreamTest, DISABLED_ChangingNetworkRoute) {
+TEST_F(VideoSendStreamTest, ChangingNetworkRoute) {
+  static const int kStartBitrateBps = 300000;
+  static const int kNewMaxBitrateBps = 1234567;
+  static const uint8_t kExtensionId = 13;
   class ChangingNetworkRouteTest : public test::EndToEndTest {
    public:
-    const int kStartBitrateBps = 300000;
-    const int kNewMaxBitrateBps = 1234567;
-
     ChangingNetworkRouteTest()
-        : EndToEndTest(test::CallTest::kDefaultTimeoutMs),
-          call_(nullptr) {}
+        : EndToEndTest(test::CallTest::kDefaultTimeoutMs), call_(nullptr) {
+      EXPECT_TRUE(parser_->RegisterRtpHeaderExtension(
+          kRtpExtensionTransportSequenceNumber, kExtensionId));
+    }
 
     void OnCallsCreated(Call* sender_call, Call* receiver_call) override {
       call_ = sender_call;
     }
 
+    void ModifyVideoConfigs(
+        VideoSendStream::Config* send_config,
+        std::vector<VideoReceiveStream::Config>* receive_configs,
+        VideoEncoderConfig* encoder_config) override {
+      send_config->rtp.extensions.clear();
+      send_config->rtp.extensions.push_back(RtpExtension(
+          RtpExtension::kTransportSequenceNumberUri, kExtensionId));
+      (*receive_configs)[0].rtp.extensions = send_config->rtp.extensions;
+      (*receive_configs)[0].rtp.transport_cc = true;
+    }
+
+    void ModifyAudioConfigs(
+        AudioSendStream::Config* send_config,
+        std::vector<AudioReceiveStream::Config>* receive_configs) override {
+      send_config->rtp.extensions.clear();
+      send_config->rtp.extensions.push_back(RtpExtension(
+          RtpExtension::kTransportSequenceNumberUri, kExtensionId));
+      (*receive_configs)[0].rtp.extensions.clear();
+      (*receive_configs)[0].rtp.extensions = send_config->rtp.extensions;
+      (*receive_configs)[0].rtp.transport_cc = true;
+    }
+
     Action OnSendRtp(const uint8_t* packet, size_t length) override {
       if (call_->GetStats().send_bandwidth_bps > kStartBitrateBps) {
         observation_complete_.Set();