Revert "Add interface_id to rtc::Network"

This reverts commit 7e91482fcc.

Reason for revert: Speculative revert, as Android FYI bots are red
starting https://webrtc.googlesource.com/src/+/7e91482fcc496103f36333a569992c81b6dc9e9c
where this CL landed.

See also https://bugs.chromium.org/p/chromium/issues/detail?id=1065805.

Original change's description:
> Add interface_id to rtc::Network
>
> This patch adds an interface_id property
> to rtc::Network. It is an enumeration of the
> interface names that are present.
>
> This enables a local ICE agent to keep track
> of which connections are using which interfaces,
> something that is useful for predicting how
> connections behave.
>
> This is part 1 of https://webrtc-review.googlesource.com/c/src/+/85520
>
> Bug: webrtc:9446
> Change-Id: Ia6ec1f14ac240799fb1be49d67d82e2733e87acf
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171061
> Reviewed-by: Harald Alvestrand <hta@webrtc.org>
> Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30882}

No-Presubmit: True
Bug: webrtc:9446
TBR=hta@webrtc.org, jonaso@webrtc.org

Change-Id: If86e2e0653b53a8eae26a97ce9fa68748b440607
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172092
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Olga Sharonova <olka@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30937}

rtc_base/network.cc

@@ -329,14 +329,8 @@ void NetworkManagerBase::MergeNetworkList(const NetworkList& new_networks,
     Network* net = kv.second.net;
     auto existing = networks_map_.find(key);
     if (existing == networks_map_.end()) {
-      if (interface_ids_by_name_.find(net->name()) ==
-          interface_ids_by_name_.end()) {
-        interface_ids_by_name_.emplace(net->name(),
-                                       next_available_interface_id_++);
-      }
-      net->set_interface_id(interface_ids_by_name_[net->name()]);
-      merged_list.push_back(net);
       // This network is new. Place it in the network map.
+      merged_list.push_back(net);
       networks_map_[key] = net;
       net->set_id(next_available_network_id_++);
       // Also, we might have accumulated IPAddresses from the first

rtc_base/network.h

@@ -207,11 +207,6 @@ class RTC_EXPORT NetworkManagerBase : public NetworkManager {
 
   IPAddress default_local_ipv4_address_;
   IPAddress default_local_ipv6_address_;
-
-  std::map<std::string, uint16_t> interface_ids_by_name_;
-  // Use 16 bits to save the bandwidth consumption when sending the interface
-  // id.
-  uint16_t next_available_interface_id_ = 1;
   // We use 16 bits to save the bandwidth consumption when sending the network
   // id over the Internet. It is OK that the 16-bit integer overflows to get a
   // network id 0 because we only compare the network ids in the old and the new
@@ -420,16 +415,6 @@ class RTC_EXPORT Network {
   uint16_t id() const { return id_; }
   void set_id(uint16_t id) { id_ = id; }
 
-  // A unique id assigned by the network manager to each network interface name.
-  // Networks on the same network interface (as identified by the interface
-  // name) have the same interface id.
-  uint16_t interface_id() const { return interface_id_; }
-  void set_interface_id(uint16_t interface_id) {
-    RTC_DCHECK(interface_id_ == 0);
-    RTC_DCHECK(interface_id != 0);
-    interface_id_ = interface_id;
-  }
-
   int preference() const { return preference_; }
   void set_preference(int preference) { preference_ = preference; }
 
@@ -462,7 +447,6 @@ class RTC_EXPORT Network {
   int preference_;
   bool active_ = true;
   uint16_t id_ = 0;
-  uint16_t interface_id_ = 0;
 
   friend class NetworkManager;
 };

rtc_base/network_unittest.cc

@@ -380,9 +380,7 @@ TEST_F(NetworkTest, TestBasicMergeNetworkList) {
   EXPECT_TRUE(SameNameAndPrefix(ipv4_network1, *list[0]));
   Network* net1 = list[0];
   uint16_t net_id1 = net1->id();
-  uint16_t net_if_id1 = net1->interface_id();
   EXPECT_EQ(1, net_id1);
-  EXPECT_EQ(1, net_if_id1);
   list.clear();
 
   // Replace ipv4_network1 with ipv4_network2.
@@ -398,10 +396,8 @@ TEST_F(NetworkTest, TestBasicMergeNetworkList) {
   EXPECT_TRUE(SameNameAndPrefix(ipv4_network2, *list[0]));
   Network* net2 = list[0];
   uint16_t net_id2 = net2->id();
-  uint16_t net_if_id2 = net2->interface_id();
   // Network id will increase.
   EXPECT_LT(net_id1, net_id2);
-  EXPECT_LT(net_if_id1, net_if_id2);
   list.clear();
 
   // Add Network2 back.
@@ -420,8 +416,6 @@ TEST_F(NetworkTest, TestBasicMergeNetworkList) {
               (net1 == list[1] && net2 == list[0]));
   EXPECT_TRUE((net_id1 == list[0]->id() && net_id2 == list[1]->id()) ||
               (net_id1 == list[1]->id() && net_id2 == list[0]->id()));
-  EXPECT_TRUE((net_if_id1 == list[0]->id() && net_if_id2 == list[1]->id()) ||
-              (net_if_id1 == list[1]->id() && net_if_id2 == list[0]->id()));
   list.clear();
 
   // Call MergeNetworkList() again and verify that we don't get update
@@ -439,60 +433,11 @@ TEST_F(NetworkTest, TestBasicMergeNetworkList) {
   EXPECT_EQ(2U, list.size());
   EXPECT_TRUE((net1 == list[0] && net2 == list[1]) ||
               (net1 == list[1] && net2 == list[0]));
-  EXPECT_TRUE((net_if_id1 == list[0]->interface_id() &&
+  EXPECT_TRUE((net_id1 == list[0]->id() && net_id2 == list[1]->id()) ||
-               net_if_id2 == list[1]->interface_id()) ||
+              (net_id1 == list[1]->id() && net_id2 == list[0]->id()));
-              (net_if_id1 == list[1]->interface_id() &&
-               net_if_id2 == list[0]->interface_id()));
   list.clear();
 }
 
-// Verify that one interface id is generated per network name.
-TEST_F(NetworkTest, TestInterfaceId) {
-  Network ipv4_network1("test_eth0", "Test Network Adapter 1",
-                        IPAddress(0x12345600U), 24);
-  Network ipv4_network2("test_eth0", "Test Network Adapter 2",
-                        IPAddress(0xaabbcc00U), 24);
-  Network ipv4_network3("test_eth1", "Test Network Adapter 2",
-                        IPAddress(0x00010000U), 16);
-  ipv4_network1.AddIP(IPAddress(0x12345678));
-  ipv4_network2.AddIP(IPAddress(0xaabbcc01));
-  ipv4_network3.AddIP(IPAddress(0x00010004));
-  BasicNetworkManager manager;
-
-  // Add list of networks.
-  {
-    NetworkManager::NetworkList list;
-    list.push_back(new Network(ipv4_network1));
-    list.push_back(new Network(ipv4_network2));
-    list.push_back(new Network(ipv4_network3));
-    bool changed;
-    NetworkManager::Stats stats = MergeNetworkList(manager, list, &changed);
-    EXPECT_TRUE(changed);
-    EXPECT_EQ(stats.ipv6_network_count, 0);
-    EXPECT_EQ(stats.ipv4_network_count, 3);
-  }
-
-  {
-    NetworkManager::NetworkList list;
-    manager.GetNetworks(&list);
-    EXPECT_EQ(list.size(), 3U);
-
-    // There should be 2 interfaces
-    std::map<int, int> networks_per_interface;
-    for (const auto& network : list) {
-      networks_per_interface[network->interface_id()]++;
-    }
-    EXPECT_EQ(networks_per_interface.size(), 2U);
-    for (const auto& network : list) {
-      if (network->name() == "test_eth0") {
-        EXPECT_EQ(networks_per_interface[network->interface_id()], 2);
-      } else {
-        EXPECT_EQ(networks_per_interface[network->interface_id()], 1);
-      }
-    }
-  }
-}
-
 // Sets up some test IPv6 networks and appends them to list.
 // Four networks are added - public and link local, for two interfaces.
 void SetupNetworks(NetworkManager::NetworkList* list) {