diff --git a/webrtc/api/peerconnection.cc b/webrtc/api/peerconnection.cc
index e1f19ad..49f9030 100644
--- a/webrtc/api/peerconnection.cc
+++ b/webrtc/api/peerconnection.cc
@@ -1298,9 +1298,16 @@
     }
   }
 
-  // TODO(deadbeef): Shouldn't have to hop to the worker thread twice...
+  // TODO(deadbeef): Shouldn't have to hop to the network thread twice...
   session_->SetIceConfig(session_->ParseIceConfig(configuration));
 
+  // As described in JSEP, calling setConfiguration with new ICE servers or
+  // candidate policy must set a "needs-ice-restart" bit so that the next offer
+  // triggers an ICE restart which will pick up the changes.
+  if (configuration.servers != configuration_.servers ||
+      configuration.type != configuration_.type) {
+    session_->SetNeedsIceRestartFlag();
+  }
   configuration_ = configuration;
   return true;
 }
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index a655756..29badbd 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -214,6 +214,11 @@
     std::vector<std::string> urls;
     std::string username;
     std::string password;
+    bool operator==(const IceServer& o) const {
+      return uri == o.uri && urls == o.urls && username == o.username &&
+             password == o.password;
+    }
+    bool operator!=(const IceServer& o) const { return !(*this == o); }
   };
   typedef std::vector<IceServer> IceServers;
 
diff --git a/webrtc/api/peerconnectioninterface_unittest.cc b/webrtc/api/peerconnectioninterface_unittest.cc
index cfba3e6..1fb3a5f 100644
--- a/webrtc/api/peerconnectioninterface_unittest.cc
+++ b/webrtc/api/peerconnectioninterface_unittest.cc
@@ -73,11 +73,11 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -86,6 +86,10 @@
     "a=ssrc:1 mslabel:stream1\r\n"
     "a=ssrc:1 label:audiotrack0\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:video\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -101,11 +105,11 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
@@ -122,12 +126,12 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "a=msid-semantic: WMS stream1 stream2\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "a=msid-semantic: WMS stream1 stream2\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -137,6 +141,10 @@
     "a=ssrc:3 cname:stream2\r\n"
     "a=ssrc:3 msid:stream2 audiotrack1\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:video\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -152,16 +160,20 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:video\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -173,17 +185,21 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "a=msid-semantic: WMS\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "a=msid-semantic: WMS\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:video\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -195,11 +211,11 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -211,17 +227,21 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
+    "m=audio 1 RTP/AVPF 103\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
     "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
-    "m=audio 1 RTP/AVPF 103\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=sendonly\r\n"
     "a=rtcp-mux\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:video\r\n"
     "a=sendrecv\r\n"
     "a=sendonly\r\n"
@@ -233,14 +253,14 @@
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
     "s=-\r\n"
     "t=0 0\r\n"
-    "a=ice-ufrag:e5785931\r\n"
-    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
-    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
-    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=msid-semantic: WMS\r\n";
 
 static const char kSdpStringAudio[] =
     "m=audio 1 RTP/AVPF 103\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:audio\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -248,6 +268,10 @@
 
 static const char kSdpStringVideo[] =
     "m=video 1 RTP/AVPF 120\r\n"
+    "a=ice-ufrag:e5785931\r\n"
+    "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
+    "a=fingerprint:sha-256 58:AB:6E:F5:F1:E4:57:B7:E9:46:F4:86:04:28:F9:A7:ED:"
+    "BD:AB:AE:40:EF:CE:9A:51:2C:2A:B1:9B:8B:78:84\r\n"
     "a=mid:video\r\n"
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
@@ -326,6 +350,18 @@
   return true;
 }
 
+// Get the ufrags out of an SDP blob. Useful for testing ICE restart
+// behavior.
+std::vector<std::string> GetUfrags(
+    const webrtc::SessionDescriptionInterface* desc) {
+  std::vector<std::string> ufrags;
+  for (const cricket::TransportInfo& info :
+       desc->description()->transport_infos()) {
+    ufrags.push_back(info.description.ice_ufrag);
+  }
+  return ufrags;
+}
+
 void SetSsrcToZero(std::string* sdp) {
   const char kSdpSsrcAtribute[] = "a=ssrc:";
   const char kSdpSsrcAtributeZero[] = "a=ssrc:0";
@@ -2727,6 +2763,116 @@
   EXPECT_EQ(observer_.last_added_track_label_, kVideoTracks[0]);
 }
 
+// Test that when SetConfiguration is called and the configuration is
+// changing, the next offer causes an ICE restart.
+TEST_F(PeerConnectionInterfaceTest, SetConfigurationCausingIceRetart) {
+  PeerConnectionInterface::RTCConfiguration config;
+  config.type = PeerConnectionInterface::kRelay;
+  // Need to pass default constraints to prevent disabling of DTLS...
+  FakeConstraints default_constraints;
+  CreatePeerConnection(config, &default_constraints);
+  AddAudioVideoStream(kStreamLabel1, "audio_label", "video_label");
+
+  // Do initial offer/answer so there's something to restart.
+  CreateOfferAsLocalDescription();
+  CreateAnswerAsRemoteDescription(kSdpStringWithStream1);
+
+  // Grab the ufrags.
+  std::vector<std::string> initial_ufrags = GetUfrags(pc_->local_description());
+
+  // Change ICE policy, which should trigger an ICE restart on the next offer.
+  config.type = PeerConnectionInterface::kAll;
+  EXPECT_TRUE(pc_->SetConfiguration(config));
+  CreateOfferAsLocalDescription();
+
+  // Grab the new ufrags.
+  std::vector<std::string> subsequent_ufrags =
+      GetUfrags(pc_->local_description());
+
+  // Sanity check.
+  EXPECT_EQ(initial_ufrags.size(), subsequent_ufrags.size());
+  // Check that each ufrag is different.
+  for (int i = 0; i < static_cast<int>(initial_ufrags.size()); ++i) {
+    EXPECT_NE(initial_ufrags[i], subsequent_ufrags[i]);
+  }
+}
+
+// Test that when SetConfiguration is called and the configuration *isn't*
+// changing, the next offer does *not* cause an ICE restart.
+TEST_F(PeerConnectionInterfaceTest, SetConfigurationNotCausingIceRetart) {
+  PeerConnectionInterface::RTCConfiguration config;
+  config.type = PeerConnectionInterface::kRelay;
+  // Need to pass default constraints to prevent disabling of DTLS...
+  FakeConstraints default_constraints;
+  CreatePeerConnection(config, &default_constraints);
+  AddAudioVideoStream(kStreamLabel1, "audio_label", "video_label");
+
+  // Do initial offer/answer so there's something to restart.
+  CreateOfferAsLocalDescription();
+  CreateAnswerAsRemoteDescription(kSdpStringWithStream1);
+
+  // Grab the ufrags.
+  std::vector<std::string> initial_ufrags = GetUfrags(pc_->local_description());
+
+  // Call SetConfiguration with a config identical to what the PC was
+  // constructed with.
+  EXPECT_TRUE(pc_->SetConfiguration(config));
+  CreateOfferAsLocalDescription();
+
+  // Grab the new ufrags.
+  std::vector<std::string> subsequent_ufrags =
+      GetUfrags(pc_->local_description());
+
+  EXPECT_EQ(initial_ufrags, subsequent_ufrags);
+}
+
+// Test for a weird corner case scenario:
+// 1. Audio/video session established.
+// 2. SetConfiguration changes ICE config; ICE restart needed.
+// 3. ICE restart initiated by remote peer, but only for one m= section.
+// 4. Next createOffer should initiate an ICE restart, but only for the other
+//    m= section; it would be pointless to do an ICE restart for the m= section
+//    that was already restarted.
+TEST_F(PeerConnectionInterfaceTest, SetConfigurationCausingPartialIceRestart) {
+  PeerConnectionInterface::RTCConfiguration config;
+  config.type = PeerConnectionInterface::kRelay;
+  // Need to pass default constraints to prevent disabling of DTLS...
+  FakeConstraints default_constraints;
+  CreatePeerConnection(config, &default_constraints);
+  AddAudioVideoStream(kStreamLabel1, "audio_label", "video_label");
+
+  // Do initial offer/answer so there's something to restart.
+  CreateOfferAsLocalDescription();
+  CreateAnswerAsRemoteDescription(kSdpStringWithStream1);
+
+  // Change ICE policy, which should set the "needs-ice-restart" flag.
+  config.type = PeerConnectionInterface::kAll;
+  EXPECT_TRUE(pc_->SetConfiguration(config));
+
+  // Do ICE restart for the first m= section, initiated by remote peer.
+  webrtc::JsepSessionDescription* remote_offer =
+      new webrtc::JsepSessionDescription(SessionDescriptionInterface::kOffer);
+  EXPECT_TRUE(remote_offer->Initialize(kSdpStringWithStream1, nullptr));
+  remote_offer->description()->transport_infos()[0].description.ice_ufrag =
+      "modified";
+  EXPECT_TRUE(DoSetRemoteDescription(remote_offer));
+  CreateAnswerAsLocalDescription();
+
+  // Grab the ufrags.
+  std::vector<std::string> initial_ufrags = GetUfrags(pc_->local_description());
+  ASSERT_EQ(2, initial_ufrags.size());
+
+  // Create offer and grab the new ufrags.
+  CreateOfferAsLocalDescription();
+  std::vector<std::string> subsequent_ufrags =
+      GetUfrags(pc_->local_description());
+  ASSERT_EQ(2, subsequent_ufrags.size());
+
+  // Ensure that only the ufrag for the second m= section changed.
+  EXPECT_EQ(initial_ufrags[0], subsequent_ufrags[0]);
+  EXPECT_NE(initial_ufrags[1], subsequent_ufrags[1]);
+}
+
 class PeerConnectionMediaConfigTest : public testing::Test {
  protected:
   void SetUp() override {
diff --git a/webrtc/api/webrtcsession.cc b/webrtc/api/webrtcsession.cc
index 636184b..c5582d3 100644
--- a/webrtc/api/webrtcsession.cc
+++ b/webrtc/api/webrtcsession.cc
@@ -1330,6 +1330,14 @@
          pending_ice_restarts_.end();
 }
 
+void WebRtcSession::SetNeedsIceRestartFlag() {
+  transport_controller_->SetNeedsIceRestartFlag();
+}
+
+bool WebRtcSession::NeedsIceRestart(const std::string& content_name) const {
+  return transport_controller_->NeedsIceRestart(content_name);
+}
+
 void WebRtcSession::OnCertificateReady(
     const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) {
   transport_controller_->SetLocalCertificate(certificate);
diff --git a/webrtc/api/webrtcsession.h b/webrtc/api/webrtcsession.h
index 94f146f..1aa3e18 100644
--- a/webrtc/api/webrtcsession.h
+++ b/webrtc/api/webrtcsession.h
@@ -278,8 +278,19 @@
 
   cricket::DataChannelType data_channel_type() const;
 
+  // Returns true if there was an ICE restart initiated by the remote offer.
   bool IceRestartPending(const std::string& content_name) const;
 
+  // Set the "needs-ice-restart" flag as described in JSEP. After the flag is
+  // set, offers should generate new ufrags/passwords until an ICE restart
+  // occurs.
+  void SetNeedsIceRestartFlag();
+  // Returns true if the ICE restart flag above was set, and no ICE restart has
+  // occurred yet for this transport (by applying a local description with
+  // changed ufrag/password). If the transport has been deleted as a result of
+  // bundling, returns false.
+  bool NeedsIceRestart(const std::string& content_name) const;
+
   // Called when an RTCCertificate is generated or retrieved by
   // WebRTCSessionDescriptionFactory. Should happen before setLocalDescription.
   void OnCertificateReady(
diff --git a/webrtc/api/webrtcsessiondescriptionfactory.cc b/webrtc/api/webrtcsessiondescriptionfactory.cc
index 29da6f2..1f811f5 100644
--- a/webrtc/api/webrtcsessiondescriptionfactory.cc
+++ b/webrtc/api/webrtcsessiondescriptionfactory.cc
@@ -338,6 +338,18 @@
 
 void WebRtcSessionDescriptionFactory::InternalCreateOffer(
     CreateSessionDescriptionRequest request) {
+  if (session_->local_description()) {
+    for (const cricket::TransportInfo& transport :
+         session_->local_description()->description()->transport_infos()) {
+      // If the needs-ice-restart flag is set as described by JSEP, we should
+      // generate an offer with a new ufrag/password to trigger an ICE restart.
+      if (session_->NeedsIceRestart(transport.content_name)) {
+        request.options.transport_options[transport.content_name].ice_restart =
+            true;
+      }
+    }
+  }
+
   cricket::SessionDescription* desc(session_desc_factory_.CreateOffer(
       request.options, session_->local_description()
                            ? session_->local_description()->description()