scheduler: Put unit test code in anonymous namespace.

components/download/internal/scheduler/network_listener_unittest.cc

Index: components/download/internal/scheduler/network_listener_unittest.cc
diff --git a/components/download/internal/scheduler/network_listener_unittest.cc b/components/download/internal/scheduler/network_listener_unittest.cc
index 189fa611fba3a0ad85a06b73c01e1841902bc31e..d488024ec04c997224be5cf93b626185935362f1 100644
--- a/components/download/internal/scheduler/network_listener_unittest.cc
+++ b/components/download/internal/scheduler/network_listener_unittest.cc
@@ -14,6 +14,7 @@ using ConnectionTypeObserver =
 using ConnectionType = net::NetworkChangeNotifier::ConnectionType;
 
 namespace download {
+namespace {
 
 // NetworkChangeNotifier that can change network type in tests.
 class TestNetworkChangeNotifier : public net::NetworkChangeNotifier {
@@ -94,4 +95,5 @@ TEST_F(NetworkListenerTest, NotifyObserverNetworkChange) {
   ChangeNetworkType(ConnectionType::CONNECTION_ETHERNET);
 }
 
+}  // namespace
 }  // namespace download