Add flakiness check if there is no received packets in a certain period.

webrtc/p2p/base/port.cc

Index: webrtc/p2p/base/port.cc
diff --git a/webrtc/p2p/base/port.cc b/webrtc/p2p/base/port.cc
index 25b5efd05689ef2e31da3ce4ac512ed4d14c61b4..d1ca8416235195934e6552f8db071b60a6427f5a 100644
--- a/webrtc/p2p/base/port.cc
+++ b/webrtc/p2p/base/port.cc
@@ -1003,7 +1003,6 @@ void Connection::OnReadPacket(
     if (read_state_ == STATE_READABLE) {
       // readable means data from this address is acceptable
       // Send it on!
-
       last_data_received_ = rtc::Time();
       recv_rate_tracker_.Update(size);
       SignalReadPacket(this, data, size, packet_time);
@@ -1444,6 +1443,11 @@ void Connection::OnMessage(rtc::Message *pmsg) {
   delete this;
 }
 
+uint32 Connection::last_received() {
+  return std::max(last_data_received_,
+             std::max(last_ping_received_, last_ping_response_received_));
+}
+
 size_t Connection::recv_bytes_second() {
   return recv_rate_tracker_.units_second();
 }