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

chromeos/network/network_state_handler.cc

Index: chromeos/network/network_state_handler.cc
diff --git a/chromeos/network/network_state_handler.cc b/chromeos/network/network_state_handler.cc
index 09c70fccd0993bad0c30581971115f9803fb57d3..de5d3017de51b207ccf1b6811e1ea277fdf09db7 100644
--- a/chromeos/network/network_state_handler.cc
+++ b/chromeos/network/network_state_handler.cc
@@ -500,7 +500,8 @@ void NetworkStateHandler::AddTetherNetworkState(const std::string& guid,
                                                 const std::string& name,
                                                 const std::string& carrier,
                                                 int battery_percentage,
-                                                int signal_strength) {
+                                                int signal_strength,
+                                                bool has_connected_to_host) {
   DCHECK(!guid.empty());
   DCHECK(battery_percentage >= 0 && battery_percentage <= 100);
   DCHECK(signal_strength >= 0 && signal_strength <= 100);
@@ -531,9 +532,7 @@ void NetworkStateHandler::AddTetherNetworkState(const std::string& guid,
   tether_network_state->set_connectable(true);
   tether_network_state->set_carrier(carrier);
   tether_network_state->set_battery_percentage(battery_percentage);
-  // TODO(khorimoto): Add this field as a parameter to this function and set it
-  // accordingly from the Tether component.
-  tether_network_state->set_tether_has_connected_to_host(false);
+  tether_network_state->set_tether_has_connected_to_host(has_connected_to_host);
   tether_network_state->set_signal_strength(signal_strength);
 
   tether_network_list_.push_back(std::move(tether_network_state));
@@ -552,8 +551,12 @@ bool NetworkStateHandler::UpdateTetherNetworkProperties(
   }
 
   NetworkState* tether_network_state = GetModifiableNetworkStateFromGuid(guid);
-  if (!tether_network_state)
+  if (!tether_network_state) {
+    NET_LOG(ERROR) << "UpdateTetherNetworkProperties() called for Tether "
+                   << "network with GUID " << guid << ", but this network is "
+                   << "not currently registered. Cannot update.";
     return false;
+  }
 
   tether_network_state->set_carrier(carrier);
   tether_network_state->set_battery_percentage(battery_percentage);
@@ -563,7 +566,27 @@ bool NetworkStateHandler::UpdateTetherNetworkProperties(
   return true;
 }
 
-void NetworkStateHandler::RemoveTetherNetworkState(const std::string& guid) {
+bool NetworkStateHandler::SetTetherNetworkHasConnectedToHost(
+    const std::string& guid) {
+  NetworkState* tether_network_state = GetModifiableNetworkStateFromGuid(guid);
+  if (!tether_network_state) {
+    NET_LOG(ERROR) << "SetTetherNetworkHasConnectedToHost() called for Tether "
+                   << "network which is not registered. GUID: " << guid;
+    return false;
+  }
+
+  bool old_tether_has_connected_to_host_value =
+      tether_network_state->tether_has_connected_to_host();
+  if (old_tether_has_connected_to_host_value) {
+    return false;
+  }
+
+  tether_network_state->set_tether_has_connected_to_host(true);
+  NotifyNetworkListChanged();
+  return true;
+}
+
+bool NetworkStateHandler::RemoveTetherNetworkState(const std::string& guid) {
   for (auto iter = tether_network_list_.begin();
        iter != tether_network_list_.end(); ++iter) {
     if (iter->get()->AsNetworkState()->guid() == guid) {
@@ -574,9 +597,11 @@ void NetworkStateHandler::RemoveTetherNetworkState(const std::string& guid) {
 
       tether_network_list_.erase(iter);
       NotifyNetworkListChanged();
-      return;
+      return true;
     }
   }
+
+  return false;
 }
 
 bool NetworkStateHandler::AssociateTetherNetworkStateWithWifiNetwork(