Reset the BWE when the network changes

webrtc/media/base/fakemediaengine.h

Index: webrtc/media/base/fakemediaengine.h
diff --git a/webrtc/media/base/fakemediaengine.h b/webrtc/media/base/fakemediaengine.h
index af05144b529e0424a4a8b89f618470f69a26e01e..a96de212eadd5eb718807620a932f65be4624038 100644
--- a/webrtc/media/base/fakemediaengine.h
+++ b/webrtc/media/base/fakemediaengine.h
@@ -20,6 +20,7 @@
 
 #include "webrtc/audio_sink.h"
 #include "webrtc/base/copyonwritebuffer.h"
+#include "webrtc/base/networkroute.h"
 #include "webrtc/base/stringutils.h"
 #include "webrtc/media/base/audiosource.h"
 #include "webrtc/media/base/mediaengine.h"
@@ -216,6 +217,8 @@ template <class Base> class RtpHelper : public Base {
   virtual void OnReadyToSend(bool ready) {
     ready_to_send_ = ready;
   }
+  virtual void OnNetworkRouteChanged(const std::string& transport_name,
+                                     const NetworkRoute& network_route) {}
   bool fail_set_send_codecs() const { return fail_set_send_codecs_; }
   bool fail_set_recv_codecs() const { return fail_set_recv_codecs_; }