arc: net: migrate to shill kMeteredProperty

Main rational for migration: user UI override settings for marking a
network metered or unmetered can only be obtained with the new
kMeteredProperty.

BUG=b:156302252
TEST=Flashed Chrome, connected the DUT to an Android hotspot with cell
tethering and checked that ARC tags the wifi hotspot as metered.

Change-Id: I83f4ca01521947edb39785053308cb88b658a69e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2217711
Commit-Queue: Hugo Benichi <hugobenichi@google.com>
Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772601}

components/arc/mojom/net.mojom

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Next MinVersion: 14
+// Next MinVersion: 15
 
 // This file defines the mojo interface between the ARC networking stack and
 // Chrome OS. There are three different groups of interactions:
@@ -126,7 +126,8 @@ enum SecurityType {
   WPA_EAP,
 };
 
-// Tethering state of a |NetworkConfiguration| as a client.
+// Deprecated enum. |is_metered| in NetworkConfiguration should be
+// used instead.
 [Extensible]
 enum TetheringClientState {
   // Tethering state is detected and confirmed.
@@ -201,9 +202,8 @@ struct NetworkConfiguration {
   // Additional WiFi properties for WiFi network services.
   WiFi? wifi;
 
-  // Indicates if the physical network is known to have upstream Internet
-  // access through tethering on a metered network.
-  [MinVersion=8] TetheringClientState tethering_client_state;
+  // Deprecated field. Uses |is_metered| instead.
+  [MinVersion=8] TetheringClientState deprecated_tethering_client_state;
 
   // The name of the network interface on the host.
   [MinVersion=10] string? network_interface;
@@ -266,6 +266,10 @@ struct NetworkConfiguration {
   // to ARC and associated with the network service. This can be different
   // from the name of the real physical interface managed by shill.
   [MinVersion=13] string? arc_network_interface;
+
+  // True if the network has been autodetected by the platform as a metered
+  // network or if the user explicitly marked the network as metered in the UI.
+  [MinVersion=14] bool is_metered;
 };
 
 // Describes a Wifi network configuration that ARC has requested the host to

components/arc/net/arc_net_host_impl.cc

@@ -228,8 +228,11 @@ arc::mojom::NetworkConfigurationPtr TranslateNetworkProperties(
   if (mojo->guid.empty())
     LOG(ERROR) << "Missing GUID property for network " << network_state->path();
   mojo->type = TranslateNetworkType(network_state->type());
-  // TODO(b/156302252) Migrate to kMeteredProperty
-  mojo->tethering_client_state =
+  mojo->is_metered =
+      shill_dict &&
+      shill_dict->FindBoolPath(shill::kMeteredProperty).value_or(false);
+  // TODO(b/156302252) Remove once ARC side has been migrated to |is_metered|.
+  mojo->deprecated_tethering_client_state =
       TranslateTetheringState(network_state->tethering_state());
 
   // IP configuration data is added from the properties of the underlying shill