Stop a session when a new connection becomes writable.

webrtc/p2p/base/p2ptransportchannel_unittest.cc

Index: webrtc/p2p/base/p2ptransportchannel_unittest.cc
diff --git a/webrtc/p2p/base/p2ptransportchannel_unittest.cc b/webrtc/p2p/base/p2ptransportchannel_unittest.cc
index 86f4ec3852300fd1043e4ab049a72d7e8514bc95..16883e2428bfad89935f25ae1452c2bc3f1864af 100644
--- a/webrtc/p2p/base/p2ptransportchannel_unittest.cc
+++ b/webrtc/p2p/base/p2ptransportchannel_unittest.cc
@@ -2159,3 +2159,25 @@ TEST_F(P2PTransportChannelPingTest, TestConnectionPrunedAgain) {
   EXPECT_TRUE_WAIT(!conn2->active(), 1000);
   EXPECT_EQ(cricket::TransportChannelState::STATE_COMPLETED, ch.GetState());
 }
+
+TEST_F(P2PTransportChannelPingTest, TestStopSessions) {

[pthatcher1, 2015/10/24 00:39:04]

Can you leave a comment about what this is testing, and perhaps make
"TestStopSessions"?  Basically, explain that if an ICE restart happens while
we're still writable, we need to stop gathering.

[honghaiz3, 2015/10/26 16:47:46]

Done. Not sure what do you mean by "make TestStopSessions".

+  cricket::FakePortAllocator pa(rtc::Thread::Current(), nullptr);
+  cricket::P2PTransportChannel ch("test channel", 1, nullptr, &pa);
+  PrepareChannel(&ch);
+  ch.SetIceConfig(CreateIceConfig(2000, false));
+  ch.Connect();
+  ch.MaybeStartGathering();
+  ch.AddRemoteCandidate(CreateCandidate("1.1.1.1", 1, 100));
+  cricket::Connection* conn1 = WaitForConnectionTo(&ch, "1.1.1.1", 1);
+  ASSERT_TRUE(conn1 != nullptr);
+  conn1->ReceivedPingResponse();  // Becomes writable and receiving
+  EXPECT_TRUE(!ch.allocator_session()->IsGettingPorts());
+
+  ch.SetIceCredentials(kIceUfrag[1], kIcePwd[1]);
+  ch.MaybeStartGathering();
+  ch.AddRemoteCandidate(CreateCandidate("2.2.2.2", 2, 100));
+  cricket::Connection* conn2 = WaitForConnectionTo(&ch, "2.2.2.2", 2);
+  ASSERT_TRUE(conn2 != nullptr);
+  conn2->ReceivedPingResponse(); // Becomes writable and receiving
+  EXPECT_TRUE(!ch.allocator_session()->IsGettingPorts());
+}