[CrOS Tether] Add HasConnectedToHost property for Tether networks.

chromeos/network/network_state_unittest.cc

Index: chromeos/network/network_state_unittest.cc
diff --git a/chromeos/network/network_state_unittest.cc b/chromeos/network/network_state_unittest.cc
index e151c96de34884a5b4fa812be6af3304cf640f75..5cd74891d191a629e059963358b1e62616cc7dc8 100644
--- a/chromeos/network/network_state_unittest.cc
+++ b/chromeos/network/network_state_unittest.cc
@@ -262,6 +262,7 @@ TEST_F(NetworkStateTest, TetherProperties) {
   network_state_.set_type(kTypeTether);
   network_state_.set_carrier("Project Fi");
   network_state_.set_battery_percentage(85);
+  network_state_.set_tether_has_connected_to_host(true);
   network_state_.set_signal_strength(75);
 
   base::DictionaryValue dictionary;
@@ -277,6 +278,11 @@ TEST_F(NetworkStateTest, TetherProperties) {
       kTetherBatteryPercentage, &battery_percentage));
   EXPECT_EQ(85, battery_percentage);
 
+  bool tether_has_connected_to_host;
+  EXPECT_TRUE(dictionary.GetBooleanWithoutPathExpansion(
+      kTetherHasConnectedToHost, &tether_has_connected_to_host));
+  EXPECT_TRUE(tether_has_connected_to_host);
+
   std::string carrier;
   EXPECT_TRUE(
       dictionary.GetStringWithoutPathExpansion(kTetherCarrier, &carrier));