[CrOS Tether] Create HostScanCache, which caches scan results and inserts them into the network sta…

chromeos/components/tether/mock_tether_host_response_recorder.cc

Index: chromeos/components/tether/mock_tether_host_response_recorder.cc
diff --git a/chromeos/components/tether/mock_tether_host_response_recorder.cc b/chromeos/components/tether/mock_tether_host_response_recorder.cc
index 483c4def615852645c77387967343662d0c45625..e3c78fe194c745c98cb0b1e1ad3dad3e51782f34 100644
--- a/chromeos/components/tether/mock_tether_host_response_recorder.cc
+++ b/chromeos/components/tether/mock_tether_host_response_recorder.cc
@@ -13,6 +13,10 @@ MockTetherHostResponseRecorder::MockTetherHostResponseRecorder()
 
 MockTetherHostResponseRecorder::~MockTetherHostResponseRecorder() {}
 
+void MockTetherHostResponseRecorder::NotifyPreviouslyConnectedHostIdsChanged() {
+  NotifyObserversPreviouslyConnectedHostIdsChanged();
+}
+
 }  // namespace tether
 
 }  // namespace chromeos