Implemented Network::GetBestIP() selection logic as following.

1) return the first global temporary and non-deprecrated ones.
2) if #1 not available, return global one.
3) if #2 not available, use ULA ipv6 as last resort.

ULA stands for unique local address. They are only useful in a private
WebRTC deployment. More detail: http://en.wikipedia.org/wiki/Unique_local_address

BUG=3808

At this point, rule #3 actually won't happen at current
implementation. The reason being that ULA address starting with 0xfc 0r 0xfd will be grouped into its own Network. The result of that is WebRTC will have one extra Network to generate candidates but the lack of rule #3 shouldn't prevent turning on IPv6 since ULA should only be tried in a close deployment anyway.

R=jiayl@webrtc.org

Committed: https://code.google.com/p/webrtc/source/detail?r=7200

Review URL: https://webrtc-codereview.appspot.com/31369004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7201 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/p2p/client/basicportallocator.cc b/talk/p2p/client/basicportallocator.cc
index 9ca873b..eda0b4b 100644
--- a/talk/p2p/client/basicportallocator.cc
+++ b/talk/p2p/client/basicportallocator.cc
@@ -431,7 +431,7 @@
       }
 
       if (!(sequence_flags & PORTALLOCATOR_ENABLE_IPV6) &&
-          networks[i]->GetBestIP().family() == AF_INET6) {
+          networks[i]->ip().family() == AF_INET6) {
         // Skip IPv6 networks unless the flag's been set.
         continue;
       }
@@ -728,7 +728,7 @@
                                        uint32 flags)
     : session_(session),
       network_(network),
-      ip_(network->GetBestIP()),
+      ip_(network->ip()),
       config_(config),
       state_(kInit),
       flags_(flags),
@@ -771,7 +771,7 @@
 
 void AllocationSequence::DisableEquivalentPhases(rtc::Network* network,
     PortConfiguration* config, uint32* flags) {
-  if (!((network == network_) && (ip_ == network->GetBestIP()))) {
+  if (!((network == network_) && (ip_ == network->ip()))) {
     // Different network setup; nothing is equivalent.
     return;
   }
diff --git a/talk/p2p/client/connectivitychecker.cc b/talk/p2p/client/connectivitychecker.cc
index 6e277a4..06de5e4 100644
--- a/talk/p2p/client/connectivitychecker.cc
+++ b/talk/p2p/client/connectivitychecker.cc
@@ -1,29 +1,5 @@
-/*
- * libjingle
- * Copyright 2004--2005, Google Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *  1. Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *  2. Redistributions in binary form must reproduce the above copyright notice,
- *     this list of conditions and the following disclaimer in the documentation
- *     and/or other materials provided with the distribution.
- *  3. The name of the author may not be used to endorse or promote products
- *     derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
- * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
+// Copyright 2011 Google Inc. All Rights Reserved.
+
 
 #include <string>
 
@@ -238,8 +214,7 @@
     return;
   }
   rtc::ProxyInfo proxy_info = request->proxy();
-  NicMap::iterator i =
-      nics_.find(NicId(networks[0]->GetBestIP(), proxy_info.address));
+  NicMap::iterator i = nics_.find(NicId(networks[0]->ip(), proxy_info.address));
   if (i != nics_.end()) {
     int port = request->port();
     uint32 now = rtc::Time();
@@ -272,7 +247,7 @@
   ASSERT(worker_ == rtc::Thread::Current());
   RelayPort* relay_port = reinterpret_cast<RelayPort*>(port);
   const ProtocolAddress* address = relay_port->ServerAddress(0);
-  rtc::IPAddress ip = port->Network()->GetBestIP();
+  rtc::IPAddress ip = port->Network()->ip();
   NicMap::iterator i = nics_.find(NicId(ip, port->proxy().address));
   if (i != nics_.end()) {
     // We have it already, add the new information.
@@ -306,7 +281,7 @@
   ASSERT(worker_ == rtc::Thread::Current());
   const std::vector<Candidate> candidates = port->Candidates();
   Candidate c = candidates[0];
-  rtc::IPAddress ip = port->Network()->GetBestIP();
+  rtc::IPAddress ip = port->Network()->ip();
   NicMap::iterator i = nics_.find(NicId(ip, port->proxy().address));
   if (i != nics_.end()) {
     // We have it already, add the new information.
@@ -325,7 +300,7 @@
 void ConnectivityChecker::OnStunPortError(Port* port) {
   ASSERT(worker_ == rtc::Thread::Current());
   LOG(LS_ERROR) << "Stun address error.";
-  rtc::IPAddress ip = port->Network()->GetBestIP();
+  rtc::IPAddress ip = port->Network()->ip();
   NicMap::iterator i = nics_.find(NicId(ip, port->proxy().address));
   if (i != nics_.end()) {
     // We have it already, add the new information.
@@ -362,28 +337,19 @@
 StunPort* ConnectivityChecker::CreateStunPort(
     const std::string& username, const std::string& password,
     const PortConfiguration* config, rtc::Network* network) {
-  return StunPort::Create(worker_,
-                          socket_factory_.get(),
-                          network,
-                          network->GetBestIP(),
-                          0,
-                          0,
-                          username,
-                          password,
-                          config->stun_servers);
+  return StunPort::Create(worker_, socket_factory_.get(),
+                          network, network->ip(), 0, 0,
+                          username, password, config->stun_servers);
 }
 
 RelayPort* ConnectivityChecker::CreateRelayPort(
     const std::string& username, const std::string& password,
     const PortConfiguration* config, rtc::Network* network) {
-  return RelayPort::Create(worker_,
-                           socket_factory_.get(),
-                           network,
-                           network->GetBestIP(),
+  return RelayPort::Create(worker_, socket_factory_.get(),
+                           network, network->ip(),
                            port_allocator_->min_port(),
                            port_allocator_->max_port(),
-                           username,
-                           password);
+                           username, password);
 }
 
 void ConnectivityChecker::CreateRelayPorts(
@@ -399,8 +365,8 @@
   for (relay = config->relays.begin();
        relay != config->relays.end(); ++relay) {
     for (uint32 i = 0; i < networks.size(); ++i) {
-      NicMap::iterator iter =
-          nics_.find(NicId(networks[i]->GetBestIP(), proxy_info.address));
+      NicMap::iterator iter = nics_.find(NicId(networks[i]->ip(),
+                                               proxy_info.address));
       if (iter != nics_.end()) {
         // TODO: Now setting the same start time for all protocols.
         // This might affect accuracy, but since we are mainly looking for
@@ -457,7 +423,7 @@
   rtc::ProxyInfo proxy_info = GetProxyInfo();
   bool allocate_relay_ports = false;
   for (uint32 i = 0; i < networks.size(); ++i) {
-    if (AddNic(networks[i]->GetBestIP(), proxy_info.address)) {
+    if (AddNic(networks[i]->ip(), proxy_info.address)) {
       Port* port = CreateStunPort(username, password, &config, networks[i]);
       if (port) {
 
@@ -534,8 +500,7 @@
     return;
   }
   rtc::ProxyInfo proxy_info = GetProxyInfo();
-  NicMap::iterator i =
-      nics_.find(NicId(networks[0]->GetBestIP(), proxy_info.address));
+  NicMap::iterator i = nics_.find(NicId(networks[0]->ip(), proxy_info.address));
   if (i != nics_.end()) {
     uint32 now = rtc::Time();
     NicInfo* nic_info = &i->second;
diff --git a/talk/p2p/client/connectivitychecker_unittest.cc b/talk/p2p/client/connectivitychecker_unittest.cc
index e206ad7..b96cf17 100644
--- a/talk/p2p/client/connectivitychecker_unittest.cc
+++ b/talk/p2p/client/connectivitychecker_unittest.cc
@@ -1,29 +1,5 @@
-/*
- * libjingle
- * Copyright 2004--2005, Google Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *  1. Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *  2. Redistributions in binary form must reproduce the above copyright notice,
- *     this list of conditions and the following disclaimer in the documentation
- *     and/or other materials provided with the distribution.
- *  3. The name of the author may not be used to endorse or promote products
- *     derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
- * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
+// Copyright 2011 Google Inc. All Rights Reserved.
+
 
 #include <string>
 
@@ -235,27 +211,19 @@
   virtual StunPort* CreateStunPort(
       const std::string& username, const std::string& password,
       const PortConfiguration* config, rtc::Network* network) {
-    return new FakeStunPort(worker(),
-                            socket_factory_,
-                            network,
-                            network->GetBestIP(),
-                            kMinPort,
-                            kMaxPort,
-                            username,
-                            password,
+    return new FakeStunPort(worker(), socket_factory_,
+                            network, network->ip(),
+                            kMinPort, kMaxPort,
+                            username, password,
                             config->stun_servers);
   }
   virtual RelayPort* CreateRelayPort(
       const std::string& username, const std::string& password,
       const PortConfiguration* config, rtc::Network* network) {
-    return new FakeRelayPort(worker(),
-                             socket_factory_,
-                             network,
-                             network->GetBestIP(),
-                             kMinPort,
-                             kMaxPort,
-                             username,
-                             password);
+    return new FakeRelayPort(worker(), socket_factory_,
+                             network, network->ip(),
+                             kMinPort, kMaxPort,
+                             username, password);
   }
   virtual void InitiateProxyDetection() {
     if (!proxy_initiated_) {
diff --git a/talk/p2p/client/fakeportallocator.h b/talk/p2p/client/fakeportallocator.h
index f80f0bd..6c36c4e 100644
--- a/talk/p2p/client/fakeportallocator.h
+++ b/talk/p2p/client/fakeportallocator.h
@@ -1,29 +1,6 @@
-/*
- * libjingle
- * Copyright 2004--2005, Google Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *  1. Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *  2. Redistributions in binary form must reproduce the above copyright notice,
- *     this list of conditions and the following disclaimer in the documentation
- *     and/or other materials provided with the distribution.
- *  3. The name of the author may not be used to endorse or promote products
- *     derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
- * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
+// Copyright 2010 Google Inc. All Rights Reserved,
+//
+// Author: Justin Uberti (juberti@google.com)
 
 #ifndef TALK_P2P_CLIENT_FAKEPORTALLOCATOR_H_
 #define TALK_P2P_CLIENT_FAKEPORTALLOCATOR_H_
@@ -62,14 +39,10 @@
 
   virtual void StartGettingPorts() {
     if (!port_) {
-      port_.reset(cricket::UDPPort::Create(worker_thread_,
-                                           factory_,
-                                           &network_,
-                                           network_.GetBestIP(),
-                                           0,
-                                           0,
-                                           username(),
-                                           password()));
+      port_.reset(cricket::UDPPort::Create(worker_thread_, factory_,
+                      &network_, network_.ip(), 0, 0,
+                      username(),
+                      password()));
       AddPort(port_.get());
     }
     ++port_config_count_;
diff --git a/webrtc/base/nat_unittest.cc b/webrtc/base/nat_unittest.cc
index 0e16259..8b9d8a1 100644
--- a/webrtc/base/nat_unittest.cc
+++ b/webrtc/base/nat_unittest.cc
@@ -209,7 +209,7 @@
   // can't talk to ip, so check for connectivity as well.
   for (std::vector<Network*>::iterator it = networks.begin();
       it != networks.end(); ++it) {
-    const IPAddress& ip = (*it)->GetBestIP();
+    const IPAddress& ip = (*it)->ip();
     if (ip.family() == int_addr.family() && TestConnectivity(int_addr, ip)) {
       ext_addr2.SetIP(ip);
       break;
diff --git a/webrtc/base/network.cc b/webrtc/base/network.cc
index c1f978b..8c84c2e 100644
--- a/webrtc/base/network.cc
+++ b/webrtc/base/network.cc
@@ -88,13 +88,10 @@
     return a->type() < b->type();
   }
 
-  IPAddress ip_a = a->GetBestIP();
-  IPAddress ip_b = b->GetBestIP();
-
   // After type, networks are sorted by IP address precedence values
   // from RFC 3484-bis
-  if (IPAddressPrecedence(ip_a) != IPAddressPrecedence(ip_b)) {
-    return IPAddressPrecedence(ip_a) > IPAddressPrecedence(ip_b);
+  if (IPAddressPrecedence(a->ip()) != IPAddressPrecedence(b->ip())) {
+    return IPAddressPrecedence(a->ip()) > IPAddressPrecedence(b->ip());
   }
 
   // TODO(mallinath) - Add VPN and Link speed conditions while sorting.
@@ -477,7 +474,7 @@
   }
   return true;
 }
-#endif  // WEBRTC_WIN
+#endif  // WEBRTC_WIN 
 
 #if defined(WEBRTC_LINUX)
 bool IsDefaultRoute(const std::string& network_name) {
@@ -639,6 +636,16 @@
       ignored_(false), type_(type), preference_(0) {
 }
 
+std::string Network::ToString() const {
+  std::stringstream ss;
+  // Print out the first space-terminated token of the network desc, plus
+  // the IP address.
+  ss << "Net[" << description_.substr(0, description_.find(' '))
+     << ":" << prefix_.ToSensitiveString() << "/" << prefix_length_
+     << ":" << AdapterTypeToString(type_) << "]";
+  return ss.str();
+}
+
 // Sets the addresses of this network. Returns true if the address set changed.
 // Change detection is short circuited if the changed argument is true.
 bool Network::SetIPs(const std::vector<InterfaceAddress>& ips, bool changed) {
@@ -662,52 +669,14 @@
   return changed;
 }
 
-// Select the best IP address to use from this Network.
-IPAddress Network::GetBestIP() const {
+// TODO(guoweis): will change the name to a more meaningful name as
+// this is not simply return the first address once the logic of ipv6
+// address selection is complete.
+IPAddress Network::ip() const {
   if (ips_.size() == 0) {
     return IPAddress();
   }
-
-  if (prefix_.family() == AF_INET) {
-    return static_cast<IPAddress>(ips_.at(0));
-  }
-
-  InterfaceAddress selected_ip, ula_ip;
-
-  for (size_t i = 0; i < ips_.size(); i++) {
-    // Ignore any address which has been deprecated already.
-    if (ips_[i].ipv6_flags() & IPV6_ADDRESS_FLAG_DEPRECATED)
-      continue;
-
-    // ULA address should only be returned when we have no other
-    // global IP.
-    if (IPIsULA(static_cast<const IPAddress&>(ips_[i]))) {
-      ula_ip = ips_[i];
-      continue;
-    }
-    selected_ip = ips_[i];
-
-    // Search could stop once a temporary non-deprecated one is found.
-    if (ips_[i].ipv6_flags() & IPV6_ADDRESS_FLAG_TEMPORARY)
-      break;
-  }
-
-  // No proper global IPv6 address found, use ULA instead.
-  if (IPIsUnspec(selected_ip) && !IPIsUnspec(ula_ip)) {
-    selected_ip = ula_ip;
-  }
-
-  return static_cast<IPAddress>(selected_ip);
-}
-
-std::string Network::ToString() const {
-  std::stringstream ss;
-  // Print out the first space-terminated token of the network desc, plus
-  // the IP address.
-  ss << "Net[" << description_.substr(0, description_.find(' '))
-     << ":" << prefix_.ToSensitiveString() << "/" << prefix_length_
-     << ":" << AdapterTypeToString(type_) << "]";
-  return ss.str();
+  return static_cast<IPAddress>(ips_.at(0));
 }
 
 }  // namespace rtc
diff --git a/webrtc/base/network.h b/webrtc/base/network.h
index 1300a9a..4cdd4d8 100644
--- a/webrtc/base/network.h
+++ b/webrtc/base/network.h
@@ -188,24 +188,19 @@
   std::string key() const { return key_; }
 
   // Returns the Network's current idea of the 'best' IP it has.
-  // Or return an unset IP if this network has no active addresses.
-  // Here is the rule on how we mark the IPv6 address as ignorable for WebRTC.
+  // 'Best' currently means the first one added.
+  // Returns an unset IP if this network has no active addresses.
+  // Here is the rule on how we mark the IPv6 address as ignorable for webrtc.
   // 1) return all global temporary dynamic and non-deprecrated ones.
-  // 2) if #1 not available, return global ones.
-  // 3) if #2 not available, use ULA ipv6 as last resort. (ULA stands
-  // for unique local address, which is not route-able in open
-  // internet but might be useful for a close WebRTC deployment.
-
-  // TODO(guoweis): rule #3 actually won't happen at current
-  // implementation. The reason being that ULA address starting with
-  // 0xfc 0r 0xfd will be grouped into its own Network. The result of
-  // that is WebRTC will have one extra Network to generate candidates
-  // but the lack of rule #3 shouldn't prevent turning on IPv6 since
-  // ULA should only be tried in a close deployment anyway.
-
+  // 2) if #1 not available, return global dynamic ones.
+  // 3) if #2 not available, return global ones.
+  // 4) if #3 not available, use ULA ipv6 as last resort.
   // Note that when not specifying any flag, it's treated as case global
-  // IPv6 address
-  IPAddress GetBestIP() const;
+  // dynamic IPv6 address
+  // TODO(guoweis): will change the name to a more meaningful name as
+  // this is not simply return the first address once the logic of ipv6
+  // address selection is complete.
+  IPAddress ip() const;
 
   // Adds an active IP address to this network. Does not check for duplicates.
   void AddIP(const InterfaceAddress& ip) { ips_.push_back(ip); }
diff --git a/webrtc/base/network_unittest.cc b/webrtc/base/network_unittest.cc
index acb118d..8123f8b 100644
--- a/webrtc/base/network_unittest.cc
+++ b/webrtc/base/network_unittest.cc
@@ -114,7 +114,7 @@
        ++it) {
     sockaddr_storage storage;
     memset(&storage, 0, sizeof(storage));
-    IPAddress ip = (*it)->GetBestIP();
+    IPAddress ip = (*it)->ip();
     SocketAddress bindaddress(ip, 0);
     bindaddress.SetScopeID((*it)->scope_id());
     // TODO(thaloun): Use rtc::AsyncSocket once it supports IPv6.
@@ -650,45 +650,4 @@
   EXPECT_EQ(list2[0]->GetIPs()[1], ip2);
 }
 
-// Test that the filtering logic follows the defined ruleset in network.h.
-TEST_F(NetworkTest, TestIPv6Selection) {
-  InterfaceAddress ip;
-  std::string ipstr;
-
-  ipstr = "2401:fa00:4:1000:be30:5bff:fee5:c3";
-  ASSERT_TRUE(IPFromString(ipstr, IPV6_ADDRESS_FLAG_DEPRECATED, &ip));
-
-  // Create a network with this prefix.
-  Network ipv6_network(
-      "test_eth0", "Test NetworkAdapter", TruncateIP(ip, 64), 64);
-
-  // When there is no address added, it should return an unspecified
-  // address.
-  EXPECT_EQ(ipv6_network.GetBestIP(), IPAddress());
-  EXPECT_TRUE(IPIsUnspec(ipv6_network.GetBestIP()));
-
-  // Deprecated one should not be returned.
-  ipv6_network.AddIP(ip);
-  EXPECT_EQ(ipv6_network.GetBestIP(), IPAddress());
-
-  // Add ULA one. ULA is unique local address which is starting either
-  // with 0xfc or 0xfd.
-  ipstr = "fd00:fa00:4:1000:be30:5bff:fee5:c4";
-  ASSERT_TRUE(IPFromString(ipstr, IPV6_ADDRESS_FLAG_NONE, &ip));
-  ipv6_network.AddIP(ip);
-  EXPECT_EQ(ipv6_network.GetBestIP(), static_cast<IPAddress>(ip));
-
-  // Add global one.
-  ipstr = "2401:fa00:4:1000:be30:5bff:fee5:c5";
-  ASSERT_TRUE(IPFromString(ipstr, IPV6_ADDRESS_FLAG_NONE, &ip));
-  ipv6_network.AddIP(ip);
-  EXPECT_EQ(ipv6_network.GetBestIP(), static_cast<IPAddress>(ip));
-
-  // Add global dynamic temporary one.
-  ipstr = "2401:fa00:4:1000:be30:5bff:fee5:c6";
-  ASSERT_TRUE(IPFromString(ipstr, IPV6_ADDRESS_FLAG_TEMPORARY, &ip));
-  ipv6_network.AddIP(ip);
-  EXPECT_EQ(ipv6_network.GetBestIP(), static_cast<IPAddress>(ip));
-}
-
 }  // namespace rtc