DTLS-SRTP set up is bypassed when the channel has been writable.

talk/app/webrtc/peerconnection_unittest.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 1214 matching lines @@
   rtc::scoped_ptr<PeerConnectionTestClient> original_peer(
       set_initializing_client(CreateDtlsClientWithAlternateKey()));
   original_peer->pc()->Close();
 
   SetSignalingReceivers();
   receiving_client()->SetExpectIceRestart(true);
   LocalP2PTest();
   VerifyRenderedSize(640, 480);
 }
 
+// This test sets up a non-bundle call and apply bundle during ICE restart. When

[pthatcher1, 2015/12/17 23:38:53]

apply => applies
during ICE restart => during an ICE restart

+// bundle is in effect in the restart, the channel can successfully reset its
+// DTLS-SRTP context.
+TEST_F(P2PTestConductor, LocalP2PTestDtlsBundleInIceRestart) {
+  MAYBE_SKIP_TEST(rtc::SSLStreamAdapter::HaveDtlsSrtp);
+  FakeConstraints setup_constraints;
+  setup_constraints.AddMandatory(MediaConstraintsInterface::kEnableDtlsSrtp,
+                                 true);
+  ASSERT_TRUE(CreateTestClients(&setup_constraints, &setup_constraints));
+  receiving_client()->RemoveBundleFromReceivedSdp(true);
+  LocalP2PTest();
+  VerifyRenderedSize(640, 480);
+
+  initializing_client()->IceRestart();
+  receiving_client()->SetExpectIceRestart(true);
+  receiving_client()->RemoveBundleFromReceivedSdp(false);
+  LocalP2PTest();
+  VerifyRenderedSize(640, 480);
+}
+
 // This test sets up a call transfer to a new callee with a different DTLS
 // fingerprint.
 TEST_F(P2PTestConductor, LocalP2PTestDtlsTransferCaller) {
   MAYBE_SKIP_TEST(rtc::SSLStreamAdapter::HaveDtlsSrtp);
   SetupAndVerifyDtlsCall();
 
   // Keeping the original peer around which will still send packets to the
   // receiving client. These SRTP packets will be dropped.
   rtc::scoped_ptr<PeerConnectionTestClient> original_peer(
       set_receiving_client(CreateDtlsClientWithAlternateKey()));
@@ skipping 713 matching lines @@
   server.urls.push_back("stun:hostname");
   server.urls.push_back("turn:hostname");
   servers.push_back(server);
   EXPECT_TRUE(webrtc::ParseIceServers(servers, &stun_configurations_,
                                       &turn_configurations_));
   EXPECT_EQ(1U, stun_configurations_.size());
   EXPECT_EQ(1U, turn_configurations_.size());
 }
 
 #endif // if !defined(THREAD_SANITIZER)