arc: net: More simple default network tracking

This patch changes how arc_net_host_impl tracks shill's default network
by directly asking NetworkStateHandler when sending NetworkConfiguration
objects over mojo instead of tracking default network changed
notifications.

In addition, an ActiveNetworksChanged notification is sent from Chrome
to ARC when a change in the default network occurs and there is more
than one active networks. This allows ARC to observe when shill changes
the relative priorities of active networks while no other network
property changes and to update Android network scores accordingly.

BUG=b:143666023
BUG=b:138351476
TEST=Deployed Chrome and ARC P on atlas, verified with Android
NetGrapher and adb shell dumpsys wifi that changing the default network
with flimflam/test/reorder-services.sh results in consistent active
network event notifications to ARC P.

Change-Id: I5b38aa58fa61613d7d61419ff6d8a7ca05f646a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1890519Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Commit-Queue: Hugo Benichi <hugobenichi@google.com>
Cr-Commit-Position: refs/heads/master@{#712846}

components/arc/net/arc_net_host_impl.cc

@@ -335,7 +335,6 @@ const chromeos::NetworkState* GetShillBackedNetwork(
 // Convenience helper for translating a vector of NetworkState objects to a
 // vector of mojo NetworkConfiguration objects.
 std::vector<arc::mojom::NetworkConfigurationPtr> TranslateNetworkStates(
-    const std::string& default_network_path,
     const std::string& arc_vpn_path,
     const chromeos::NetworkStateHandler::NetworkStateList& network_states) {
   std::vector<arc::mojom::NetworkConfigurationPtr> networks;
@@ -355,7 +354,8 @@ std::vector<arc::mojom::NetworkConfigurationPtr> TranslateNetworkStates(
     }
     auto network = TranslateONCConfiguration(
         state, chromeos::network_util::TranslateNetworkStateToONC(state).get());
-    network->is_default_network = network_path == default_network_path;
+    network->is_default_network =
+        (network_path == GetStateHandler()->default_network_path());
     networks.push_back(std::move(network));
   }
   return networks;
@@ -553,8 +553,8 @@ void ArcNetHostImpl::GetNetworks(mojom::GetNetworksRequestType type,
         kGetNetworksListLimit, &network_states);
   }
 
-  std::vector<mojom::NetworkConfigurationPtr> networks = TranslateNetworkStates(
-      default_network_path_, arc_vpn_service_path_, network_states);
+  std::vector<mojom::NetworkConfigurationPtr> networks =
+      TranslateNetworkStates(arc_vpn_service_path_, network_states);
   std::move(callback).Run(mojom::GetNetworksResponseType::New(
       arc::mojom::NetworkResult::SUCCESS, std::move(networks)));
 }
@@ -797,7 +797,6 @@ void ArcNetHostImpl::UpdateDefaultNetwork() {
 
   if (!default_network) {
     VLOG(1) << "No default network";
-    default_network_path_.clear();
     auto* net_instance = ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service_->net(),
                                                      DefaultNetworkChanged);
     if (net_instance)
@@ -807,7 +806,6 @@ void ArcNetHostImpl::UpdateDefaultNetwork() {
 
   VLOG(1) << "New default network: " << default_network->path() << " ("
           << default_network->type() << ")";
-  default_network_path_ = default_network->path();
   std::string user_id_hash = chromeos::LoginState::Get()->primary_user_hash();
   GetManagedConfigurationHandler()->GetProperties(
       user_id_hash, default_network->path(),
@@ -819,6 +817,15 @@ void ArcNetHostImpl::UpdateDefaultNetwork() {
 void ArcNetHostImpl::DefaultNetworkChanged(
     const chromeos::NetworkState* network) {
   UpdateDefaultNetwork();
+
+  // If the the default network switched between two networks, also send an
+  // ActiveNetworkChanged notification to let ARC observe the switch.
+  chromeos::NetworkStateHandler::NetworkStateList network_states;
+  GetStateHandler()->GetActiveNetworkListByType(
+      chromeos::NetworkTypePattern::Default(), &network_states);
+  if (network_states.size() > 1) {
+    ActiveNetworksChanged(network_states);
+  }
 }
 
 void ArcNetHostImpl::DeviceListChanged() {
@@ -1046,8 +1053,7 @@ void ArcNetHostImpl::ActiveNetworksChanged(
     return;
 
   std::vector<arc::mojom::NetworkConfigurationPtr> network_configurations =
-      TranslateNetworkStates(default_network_path_, arc_vpn_service_path_,
-                             active_networks);
+      TranslateNetworkStates(arc_vpn_service_path_, active_networks);
   net_instance->ActiveNetworksChanged(std::move(network_configurations));
 }
 

components/arc/net/arc_net_host_impl.h

@@ -159,7 +159,6 @@ class ArcNetHostImpl : public KeyedService,
 
   std::string cached_service_path_;
   std::string cached_guid_;
-  std::string default_network_path_;
   std::string arc_vpn_service_path_;
   // Owned by the user profile whose context was used to initialize |this|.
   PrefService* pref_service_ = nullptr;