Replace use of ASSERT in test code.

webrtc/base/network_unittest.cc

Index: webrtc/base/network_unittest.cc
diff --git a/webrtc/base/network_unittest.cc b/webrtc/base/network_unittest.cc
index ab5df738fb8013945db87157abac464b9122d1f2..2c05b059cc6899de2b4910f9a27d8c3a13730a49 100644
--- a/webrtc/base/network_unittest.cc
+++ b/webrtc/base/network_unittest.cc
@@ -10,6 +10,7 @@
 
 #include "webrtc/base/network.h"
 
+#include "webrtc/base/checks.h"
 #include "webrtc/base/nethelpers.h"
 #include "webrtc/base/networkmonitor.h"
 #include <memory>
@@ -103,7 +104,7 @@ class NetworkTest : public testing::Test, public sigslot::has_slots<>  {
   AdapterType GetAdapterType(BasicNetworkManager& network_manager) {
     BasicNetworkManager::NetworkList list;
     network_manager.GetNetworks(&list);
-    ASSERT(list.size() == 1u);
+    RTC_CHECK(list.size() == 1u);
     return list[0]->type();
   }