Make the state transition for a PortAllocatorSession in each derived class

webrtc/p2p/base/fakeportallocator.h

Index: webrtc/p2p/base/fakeportallocator.h
diff --git a/webrtc/p2p/base/fakeportallocator.h b/webrtc/p2p/base/fakeportallocator.h
index 15e793769481dac4ac3bde5d224381e2dc9aab52..001308543ea47e7692949a4e77d1c13343618e2e 100644
--- a/webrtc/p2p/base/fakeportallocator.h
+++ b/webrtc/p2p/base/fakeportallocator.h
@@ -123,7 +123,6 @@ class FakePortAllocatorSession : public PortAllocatorSession {
   }
 
   void StartGettingPorts() override {
-    PortAllocatorSession::StartGettingPorts();
     if (!port_) {
       rtc::Network& network =
           (rtc::HasIPv6Enabled() && (flags() & PORTALLOCATOR_ENABLE_IPV6))
@@ -137,8 +136,13 @@ class FakePortAllocatorSession : public PortAllocatorSession {
       AddPort(port_.get());
     }
     ++port_config_count_;
+    running_ = true;
   }
 
+  void StopGettingPorts() override { running_ = false; }
+  bool IsGettingPorts() override { return running_; }
+  void ClearGettingPorts() override {}
+
   std::vector<PortInterface*> ReadyPorts() const override {
     return ready_ports_;
   }
@@ -204,6 +208,7 @@ class FakePortAllocatorSession : public PortAllocatorSession {
   std::vector<RelayServerConfig> turn_servers_;
   uint32_t candidate_filter_ = CF_ALL;
   int transport_info_update_count_ = 0;
+  bool running_ = false;
 };
 
 class FakePortAllocator : public cricket::PortAllocator {