Relanding: Move "max IPv6 networks" logic to BasicPortAllocator, and fix sorting.

webrtc/rtc_base/network.h

Index: webrtc/rtc_base/network.h
diff --git a/webrtc/rtc_base/network.h b/webrtc/rtc_base/network.h
index 4cbbfefd42dc43428d7fc97b4801faee7c97750d..ceb96c476053ee3f427665526e1c6896e7f76f99 100644
--- a/webrtc/rtc_base/network.h
+++ b/webrtc/rtc_base/network.h
@@ -147,13 +147,13 @@ class NetworkManagerBase : public NetworkManager {
 
   void GetNetworks(NetworkList* networks) const override;
   void GetAnyAddressNetworks(NetworkList* networks) override;
+
   // Defaults to true.
+  // TODO(deadbeef): Remove this. Nothing but tests use this; IPv6 is enabled
+  // by default everywhere else.
   bool ipv6_enabled() const { return ipv6_enabled_; }
   void set_ipv6_enabled(bool enabled) { ipv6_enabled_ = enabled; }
 
-  void set_max_ipv6_networks(int networks) { max_ipv6_networks_ = networks; }
-  int max_ipv6_networks() { return max_ipv6_networks_; }
-
   EnumerationPermission enumeration_permission() const override;
 
   bool GetDefaultLocalAddress(int family, IPAddress* ipaddr) const override;
@@ -187,7 +187,6 @@ class NetworkManagerBase : public NetworkManager {
   EnumerationPermission enumeration_permission_;
 
   NetworkList networks_;
-  int max_ipv6_networks_;
 
   NetworkMap networks_map_;
   bool ipv6_enabled_;