Add ADAPTER_TYPE_ANY in AdapterType.

ADAPTER_TYPE_ANY can be used to set the network ignore mask if an
application does not want candidates from the any address ports, the
underlying network interface types of which are not determined in
gathering. The ADAPTER_TYPE_ANY is also given the maximum network cost
so that when there are candidates from explicit network interfaces,
these candidates from the any address ports as backups, if they ever
surface, are not preferred if the other candidates have at least the
same network condition.

Bug: webrtc:9468
Change-Id: I20c3a40e9a75b8fb34fad741ba5f835ecc3b0d92
Reviewed-on: https://webrtc-review.googlesource.com/85880
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Commit-Queue: Qingsi Wang <qingsi@google.com>
Cr-Commit-Position: refs/heads/master@{#23807}

pc/rtcstatscollector.cc

@@ -168,6 +168,7 @@ const char* NetworkAdapterTypeToStatsType(rtc::AdapterType type) {
       return RTCNetworkType::kVpn;
     case rtc::ADAPTER_TYPE_UNKNOWN:
     case rtc::ADAPTER_TYPE_LOOPBACK:
+    case rtc::ADAPTER_TYPE_ANY:
       return RTCNetworkType::kUnknown;
   }
   RTC_NOTREACHED();

pc/statscollector.cc

@@ -414,6 +414,7 @@ const char* IceCandidateTypeToStatsType(const std::string& candidate_type) {
 
 const char* AdapterTypeToStatsType(rtc::AdapterType type) {
   switch (type) {
+    case rtc::ADAPTER_TYPE_ANY:
     case rtc::ADAPTER_TYPE_UNKNOWN:
       return "unknown";
     case rtc::ADAPTER_TYPE_ETHERNET: