remoting/host/cast_extension_session.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "remoting/host/cast_extension_session.h"
   6
   7 #include "base/bind.h"
   8 #include "base/json/json_reader.h"
   9 #include "base/json/json_writer.h"
  10 #include "base/logging.h"
  11 #include "base/synchronization/waitable_event.h"
  12 #include "net/url_request/url_request_context_getter.h"
  13 #include "remoting/host/cast_video_capturer_adapter.h"
  14 #include "remoting/host/chromium_port_allocator_factory.h"
  15 #include "remoting/host/client_session.h"
  16 #include "remoting/proto/control.pb.h"
  17 #include "remoting/protocol/client_stub.h"
  18 #include "third_party/libjingle/source/talk/app/webrtc/mediastreaminterface.h"
  19 #include "third_party/libjingle/source/talk/app/webrtc/test/fakeconstraints.h"
  20 #include "third_party/libjingle/source/talk/app/webrtc/videosourceinterface.h"
  21
  22 namespace remoting {
  23
  24 // Used as the type attribute of all Cast protocol::ExtensionMessages.
  25 const char kExtensionMessageType[] = "cast_message";
  26
  27 // Top-level keys used in all extension messages between host and client.
  28 // Must keep synced with webapp.
  29 const char kTopLevelData[] = "chromoting_data";
  30 const char kTopLevelSubject[] = "subject";
  31
  32 // Keys used to describe the subject of a cast extension message. WebRTC-related
  33 // message subjects are prepended with "webrtc_".
  34 // Must keep synced with webapp.
  35 const char kSubjectReady[] = "ready";
  36 const char kSubjectTest[] = "test";
  37 const char kSubjectNewCandidate[] = "webrtc_candidate";
  38 const char kSubjectOffer[] = "webrtc_offer";
  39 const char kSubjectAnswer[] = "webrtc_answer";
  40
  41 // WebRTC headers used inside messages with subject = "webrtc_*".
  42 const char kWebRtcCandidate[] = "candidate";
  43 const char kWebRtcSessionDescType[] = "type";
  44 const char kWebRtcSessionDescSDP[] = "sdp";
  45 const char kWebRtcSDPMid[] = "sdpMid";
  46 const char kWebRtcSDPMLineIndex[] = "sdpMLineIndex";
  47
  48 // Media labels used over the PeerConnection.
  49 const char kVideoLabel[] = "cast_video_label";
  50 const char kStreamLabel[] = "stream_label";
  51
  52 // Default STUN server used to construct
  53 // webrtc::PeerConnectionInterface::RTCConfiguration for the PeerConnection.
  54 const char kDefaultStunURI[] = "stun:stun.l.google.com:19302";
  55
  56 const char kWorkerThreadName[] = "CastExtensionSessionWorkerThread";
  57
  58 // Interval between each call to PollPeerConnectionStats().
  59 const int kStatsLogIntervalSec = 10;
  60
  61 // Minimum frame rate for video streaming over the PeerConnection in frames per
  62 // second, added as a media constraint when constructing the video source for
  63 // the Peer Connection.
  64 const int kMinFramesPerSecond = 5;
  65
  66 // A webrtc::SetSessionDescriptionObserver implementation used to receive the
  67 // results of setting local and remote descriptions of the PeerConnection.
  68 class CastSetSessionDescriptionObserver
  69     : public webrtc::SetSessionDescriptionObserver {
  70  public:
  71   static CastSetSessionDescriptionObserver* Create() {
  72     return new rtc::RefCountedObject<CastSetSessionDescriptionObserver>();
  73   }
  74   virtual void OnSuccess() OVERRIDE {
  75     VLOG(1) << "Setting session description succeeded.";
  76   }
  77   virtual void OnFailure(const std::string& error) OVERRIDE {
  78     LOG(ERROR) << "Setting session description failed: " << error;
  79   }
  80
  81  protected:
  82   CastSetSessionDescriptionObserver() {}
  83   virtual ~CastSetSessionDescriptionObserver() {}
  84
  85   DISALLOW_COPY_AND_ASSIGN(CastSetSessionDescriptionObserver);
  86 };
  87
  88 // A webrtc::CreateSessionDescriptionObserver implementation used to receive the
  89 // results of creating descriptions for this end of the PeerConnection.
  90 class CastCreateSessionDescriptionObserver
  91     : public webrtc::CreateSessionDescriptionObserver {
  92  public:
  93   static CastCreateSessionDescriptionObserver* Create(
  94       CastExtensionSession* session) {
  95     return new rtc::RefCountedObject<CastCreateSessionDescriptionObserver>(
  96         session);
  97   }
  98   virtual void OnSuccess(webrtc::SessionDescriptionInterface* desc) OVERRIDE {
  99     if (cast_extension_session_ == NULL) {
 100       LOG(ERROR)
 101           << "No CastExtensionSession. Creating session description succeeded.";
 102       return;
 103     }
 104     cast_extension_session_->OnCreateSessionDescription(desc);
 105   }
 106   virtual void OnFailure(const std::string& error) OVERRIDE {
 107     if (cast_extension_session_ == NULL) {
 108       LOG(ERROR)
 109           << "No CastExtensionSession. Creating session description failed.";
 110       return;
 111     }
 112     cast_extension_session_->OnCreateSessionDescriptionFailure(error);
 113   }
 114   void SetCastExtensionSession(CastExtensionSession* cast_extension_session) {
 115     cast_extension_session_ = cast_extension_session;
 116   }
 117
 118  protected:
 119   explicit CastCreateSessionDescriptionObserver(CastExtensionSession* session)
 120       : cast_extension_session_(session) {}
 121   virtual ~CastCreateSessionDescriptionObserver() {}
 122
 123  private:
 124   CastExtensionSession* cast_extension_session_;
 125
 126   DISALLOW_COPY_AND_ASSIGN(CastCreateSessionDescriptionObserver);
 127 };
 128
 129 // A webrtc::StatsObserver implementation used to receive statistics about the
 130 // current PeerConnection.
 131 class CastStatsObserver : public webrtc::StatsObserver {
 132  public:
 133   static CastStatsObserver* Create() {
 134     return new rtc::RefCountedObject<CastStatsObserver>();
 135   }
 136
 137   virtual void OnComplete(
 138       const std::vector<webrtc::StatsReport>& reports) OVERRIDE {
 139     typedef webrtc::StatsReport::Values::iterator ValuesIterator;
 140
 141     VLOG(1) << "Received " << reports.size() << " new StatsReports.";
 142
 143     int index;
 144     std::vector<webrtc::StatsReport>::const_iterator it;
 145     for (it = reports.begin(), index = 0; it != reports.end(); ++it, ++index) {
 146       webrtc::StatsReport::Values v = it->values;
 147       VLOG(1) << "Report " << index << ":";
 148       for (ValuesIterator vIt = v.begin(); vIt != v.end(); ++vIt) {
 149         VLOG(1) << "Stat: " << vIt->name << "=" << vIt->value << ".";
 150       }
 151     }
 152   }
 153
 154  protected:
 155   CastStatsObserver() {}
 156   virtual ~CastStatsObserver() {}
 157
 158   DISALLOW_COPY_AND_ASSIGN(CastStatsObserver);
 159 };
 160
 161 // TODO(aiguha): Fix PeerConnnection-related tear down crash caused by premature
 162 // destruction of cricket::CaptureManager (which occurs on releasing
 163 // |peer_conn_factory_|). See crbug.com/403840.
 164 CastExtensionSession::~CastExtensionSession() {
 165   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 166
 167   // Explicitly clear |create_session_desc_observer_|'s pointer to |this|,
 168   // since the CastExtensionSession is destructing. Otherwise,
 169   // |create_session_desc_observer_| would be left with a dangling pointer.
 170   create_session_desc_observer_->SetCastExtensionSession(NULL);
 171
 172   CleanupPeerConnection();
 173 }
 174
 175 // static
 176 scoped_ptr<CastExtensionSession> CastExtensionSession::Create(
 177     scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner,
 178     scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
 179     const protocol::NetworkSettings& network_settings,
 180     ClientSessionControl* client_session_control,
 181     protocol::ClientStub* client_stub) {
 182   scoped_ptr<CastExtensionSession> cast_extension_session(
 183       new CastExtensionSession(caller_task_runner,
 184                                url_request_context_getter,
 185                                network_settings,
 186                                client_session_control,
 187                                client_stub));
 188   if (!cast_extension_session->WrapTasksAndSave()) {
 189     return scoped_ptr<CastExtensionSession>();
 190   }
 191   if (!cast_extension_session->InitializePeerConnection()) {
 192     return scoped_ptr<CastExtensionSession>();
 193   }
 194   return cast_extension_session.Pass();
 195 }
 196
 197 void CastExtensionSession::OnCreateSessionDescription(
 198     webrtc::SessionDescriptionInterface* desc) {
 199   if (!caller_task_runner_->BelongsToCurrentThread()) {
 200     caller_task_runner_->PostTask(
 201         FROM_HERE,
 202         base::Bind(&CastExtensionSession::OnCreateSessionDescription,
 203                    base::Unretained(this),
 204                    desc));
 205     return;
 206   }
 207
 208   peer_connection_->SetLocalDescription(
 209       CastSetSessionDescriptionObserver::Create(), desc);
 210
 211   scoped_ptr<base::DictionaryValue> json(new base::DictionaryValue());
 212   json->SetString(kWebRtcSessionDescType, desc->type());
 213   std::string subject =
 214       (desc->type() == "offer") ? kSubjectOffer : kSubjectAnswer;
 215   std::string desc_str;
 216   desc->ToString(&desc_str);
 217   json->SetString(kWebRtcSessionDescSDP, desc_str);
 218   std::string json_str;
 219   if (!base::JSONWriter::Write(json.get(), &json_str)) {
 220     LOG(ERROR) << "Failed to serialize sdp message.";
 221     return;
 222   }
 223
 224   SendMessageToClient(subject.c_str(), json_str);
 225 }
 226
 227 void CastExtensionSession::OnCreateSessionDescriptionFailure(
 228     const std::string& error) {
 229   VLOG(1) << "Creating Session Description failed: " << error;
 230 }
 231
 232 // TODO(aiguha): Support the case(s) where we've grabbed the capturer already,
 233 // but another extension reset the video pipeline. We should remove the
 234 // stream from the peer connection here, and then attempt to re-setup the
 235 // peer connection in the OnRenegotiationNeeded() callback.
 236 // See crbug.com/403843.
 237 void CastExtensionSession::OnCreateVideoCapturer(
 238     scoped_ptr<webrtc::DesktopCapturer>* capturer) {
 239   if (has_grabbed_capturer_) {
 240     LOG(ERROR) << "The video pipeline was reset unexpectedly.";
 241     has_grabbed_capturer_ = false;
 242     peer_connection_->RemoveStream(stream_.release());
 243     return;
 244   }
 245
 246   if (received_offer_) {
 247     has_grabbed_capturer_ = true;
 248     if (SetupVideoStream(capturer->Pass())) {
 249       peer_connection_->CreateAnswer(create_session_desc_observer_, NULL);
 250     } else {
 251       has_grabbed_capturer_ = false;
 252       // Ignore the received offer, since we failed to setup a video stream.
 253       received_offer_ = false;
 254     }
 255     return;
 256   }
 257 }
 258
 259 bool CastExtensionSession::ModifiesVideoPipeline() const {
 260   return true;
 261 }
 262
 263 // Returns true if the |message| is a Cast ExtensionMessage, even if
 264 // it was badly formed or a resulting action failed. This is done so that
 265 // the host does not continue to attempt to pass |message| to other
 266 // HostExtensionSessions.
 267 bool CastExtensionSession::OnExtensionMessage(
 268     ClientSessionControl* client_session_control,
 269     protocol::ClientStub* client_stub,
 270     const protocol::ExtensionMessage& message) {
 271   if (message.type() != kExtensionMessageType) {
 272     return false;
 273   }
 274
 275   scoped_ptr<base::Value> value(base::JSONReader::Read(message.data()));
 276   base::DictionaryValue* client_message;
 277   if (!(value && value->GetAsDictionary(&client_message))) {
 278     LOG(ERROR) << "Could not read cast extension message.";
 279     return true;
 280   }
 281
 282   std::string subject;
 283   if (!client_message->GetString(kTopLevelSubject, &subject)) {
 284     LOG(ERROR) << "Invalid Cast Extension Message (missing subject header).";
 285     return true;
 286   }
 287
 288   if (subject == kSubjectOffer && !received_offer_) {
 289     // Reset the video pipeline so we can grab the screen capturer and setup
 290     // a video stream.
 291     if (ParseAndSetRemoteDescription(client_message)) {
 292       received_offer_ = true;
 293       LOG(INFO) << "About to ResetVideoPipeline.";
 294       client_session_control_->ResetVideoPipeline();
 295
 296     }
 297   } else if (subject == kSubjectAnswer) {
 298     ParseAndSetRemoteDescription(client_message);
 299   } else if (subject == kSubjectNewCandidate) {
 300     ParseAndAddICECandidate(client_message);
 301   } else {
 302     VLOG(1) << "Unexpected CastExtension Message: " << message.data();
 303   }
 304   return true;
 305 }
 306
 307 // Private methods ------------------------------------------------------------
 308
 309 CastExtensionSession::CastExtensionSession(
 310     scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner,
 311     scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
 312     const protocol::NetworkSettings& network_settings,
 313     ClientSessionControl* client_session_control,
 314     protocol::ClientStub* client_stub)
 315     : caller_task_runner_(caller_task_runner),
 316       url_request_context_getter_(url_request_context_getter),
 317       network_settings_(network_settings),
 318       client_session_control_(client_session_control),
 319       client_stub_(client_stub),
 320       stats_observer_(CastStatsObserver::Create()),
 321       received_offer_(false),
 322       has_grabbed_capturer_(false),
 323       signaling_thread_wrapper_(NULL),
 324       worker_thread_wrapper_(NULL),
 325       worker_thread_(kWorkerThreadName) {
 326   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 327   DCHECK(url_request_context_getter_.get());
 328   DCHECK(client_session_control_);
 329   DCHECK(client_stub_);
 330
 331   // The worker thread is created with base::MessageLoop::TYPE_IO because
 332   // the PeerConnection performs some port allocation operations on this thread
 333   // that require it. See crbug.com/404013.
 334   base::Thread::Options options(base::MessageLoop::TYPE_IO, 0);
 335   worker_thread_.StartWithOptions(options);
 336   worker_task_runner_ = worker_thread_.task_runner();
 337 }
 338
 339 bool CastExtensionSession::ParseAndSetRemoteDescription(
 340     base::DictionaryValue* message) {
 341   DCHECK(peer_connection_.get() != NULL);
 342
 343   base::DictionaryValue* message_data;
 344   if (!message->GetDictionary(kTopLevelData, &message_data)) {
 345     LOG(ERROR) << "Invalid Cast Extension Message (missing data).";
 346     return false;
 347   }
 348
 349   std::string webrtc_type;
 350   if (!message_data->GetString(kWebRtcSessionDescType, &webrtc_type)) {
 351     LOG(ERROR)
 352         << "Invalid Cast Extension Message (missing webrtc type header).";
 353     return false;
 354   }
 355
 356   std::string sdp;
 357   if (!message_data->GetString(kWebRtcSessionDescSDP, &sdp)) {
 358     LOG(ERROR) << "Invalid Cast Extension Message (missing webrtc sdp header).";
 359     return false;
 360   }
 361
 362   webrtc::SdpParseError error;
 363   webrtc::SessionDescriptionInterface* session_description(
 364       webrtc::CreateSessionDescription(webrtc_type, sdp, &error));
 365
 366   if (!session_description) {
 367     LOG(ERROR) << "Invalid Cast Extension Message (could not parse sdp).";
 368     VLOG(1) << "SdpParseError was: " << error.description;
 369     return false;
 370   }
 371
 372   peer_connection_->SetRemoteDescription(
 373       CastSetSessionDescriptionObserver::Create(), session_description);
 374   return true;
 375 }
 376
 377 bool CastExtensionSession::ParseAndAddICECandidate(
 378     base::DictionaryValue* message) {
 379   DCHECK(peer_connection_.get() != NULL);
 380
 381   base::DictionaryValue* message_data;
 382   if (!message->GetDictionary(kTopLevelData, &message_data)) {
 383     LOG(ERROR) << "Invalid Cast Extension Message (missing data).";
 384     return false;
 385   }
 386
 387   std::string candidate_str;
 388   std::string sdp_mid;
 389   int sdp_mlineindex = 0;
 390   if (!message_data->GetString(kWebRtcSDPMid, &sdp_mid) ||
 391       !message_data->GetInteger(kWebRtcSDPMLineIndex, &sdp_mlineindex) ||
 392       !message_data->GetString(kWebRtcCandidate, &candidate_str)) {
 393     LOG(ERROR) << "Invalid Cast Extension Message (could not parse).";
 394     return false;
 395   }
 396
 397   rtc::scoped_ptr<webrtc::IceCandidateInterface> candidate(
 398       webrtc::CreateIceCandidate(sdp_mid, sdp_mlineindex, candidate_str));
 399   if (!candidate.get()) {
 400     LOG(ERROR)
 401         << "Invalid Cast Extension Message (could not create candidate).";
 402     return false;
 403   }
 404
 405   if (!peer_connection_->AddIceCandidate(candidate.get())) {
 406     LOG(ERROR) << "Failed to apply received ICE Candidate to PeerConnection.";
 407     return false;
 408   }
 409
 410   VLOG(1) << "Received and Added ICE Candidate: " << candidate_str;
 411
 412   return true;
 413 }
 414
 415 bool CastExtensionSession::SendMessageToClient(const std::string& subject,
 416                                                const std::string& data) {
 417   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 418
 419   if (client_stub_ == NULL) {
 420     LOG(ERROR) << "No Client Stub. Cannot send message to client.";
 421     return false;
 422   }
 423
 424   base::DictionaryValue message_dict;
 425   message_dict.SetString(kTopLevelSubject, subject);
 426   message_dict.SetString(kTopLevelData, data);
 427   std::string message_json;
 428
 429   if (!base::JSONWriter::Write(&message_dict, &message_json)) {
 430     LOG(ERROR) << "Failed to serialize JSON message.";
 431     return false;
 432   }
 433
 434   protocol::ExtensionMessage message;
 435   message.set_type(kExtensionMessageType);
 436   message.set_data(message_json);
 437   client_stub_->DeliverHostMessage(message);
 438   return true;
 439 }
 440
 441 void CastExtensionSession::EnsureTaskAndSetSend(rtc::Thread** ptr,
 442                                                 base::WaitableEvent* event) {
 443   jingle_glue::JingleThreadWrapper::EnsureForCurrentMessageLoop();
 444   jingle_glue::JingleThreadWrapper::current()->set_send_allowed(true);
 445   *ptr = jingle_glue::JingleThreadWrapper::current();
 446
 447   if (event != NULL) {
 448     event->Signal();
 449   }
 450 }
 451
 452 bool CastExtensionSession::WrapTasksAndSave() {
 453   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 454
 455   EnsureTaskAndSetSend(&signaling_thread_wrapper_);
 456   if (signaling_thread_wrapper_ == NULL)
 457     return false;
 458
 459   base::WaitableEvent wrap_worker_thread_event(true, false);
 460   worker_task_runner_->PostTask(
 461       FROM_HERE,
 462       base::Bind(&CastExtensionSession::EnsureTaskAndSetSend,
 463                  base::Unretained(this),
 464                  &worker_thread_wrapper_,
 465                  &wrap_worker_thread_event));
 466   wrap_worker_thread_event.Wait();
 467
 468   return (worker_thread_wrapper_ != NULL);
 469 }
 470
 471 bool CastExtensionSession::InitializePeerConnection() {
 472   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 473   DCHECK(!peer_conn_factory_);
 474   DCHECK(!peer_connection_);
 475   DCHECK(worker_thread_wrapper_ != NULL);
 476   DCHECK(signaling_thread_wrapper_ != NULL);
 477
 478   peer_conn_factory_ = webrtc::CreatePeerConnectionFactory(
 479       worker_thread_wrapper_, signaling_thread_wrapper_, NULL, NULL, NULL);
 480
 481   if (!peer_conn_factory_.get()) {
 482     CleanupPeerConnection();
 483     return false;
 484   }
 485
 486   VLOG(1) << "Created PeerConnectionFactory successfully.";
 487
 488   webrtc::PeerConnectionInterface::IceServers servers;
 489   webrtc::PeerConnectionInterface::IceServer server;
 490   server.uri = kDefaultStunURI;
 491   servers.push_back(server);
 492   webrtc::PeerConnectionInterface::RTCConfiguration rtc_config;
 493   rtc_config.servers = servers;
 494
 495   // DTLS-SRTP is the preferred encryption method. If set to kValueFalse, the
 496   // peer connection uses SDES. Disabling SDES as well will cause the peer
 497   // connection to fail to connect.
 498   // Note: For protection and unprotection of SRTP packets, the libjingle
 499   // ENABLE_EXTERNAL_AUTH flag must not be set.
 500   webrtc::FakeConstraints constraints;
 501   constraints.AddMandatory(webrtc::MediaConstraintsInterface::kEnableDtlsSrtp,
 502                            webrtc::MediaConstraintsInterface::kValueTrue);
 503
 504   rtc::scoped_refptr<webrtc::PortAllocatorFactoryInterface>
 505       port_allocator_factory = ChromiumPortAllocatorFactory::Create(
 506           network_settings_, url_request_context_getter_);
 507
 508   peer_connection_ = peer_conn_factory_->CreatePeerConnection(
 509       rtc_config, &constraints, port_allocator_factory, NULL, this);
 510
 511   if (!peer_connection_.get()) {
 512     CleanupPeerConnection();
 513     return false;
 514   }
 515
 516   VLOG(1) << "Created PeerConnection successfully.";
 517
 518   create_session_desc_observer_ =
 519       CastCreateSessionDescriptionObserver::Create(this);
 520
 521   // Send a test message to the client. Then, notify the client to start
 522   // webrtc offer/answer negotiation.
 523   if (!SendMessageToClient(kSubjectTest, "Hello, client.") ||
 524       !SendMessageToClient(kSubjectReady, "Host ready to receive offers.")) {
 525     LOG(ERROR) << "Failed to send messages to client.";
 526     return false;
 527   }
 528
 529   return true;
 530 }
 531
 532 bool CastExtensionSession::SetupVideoStream(
 533     scoped_ptr<webrtc::DesktopCapturer> desktop_capturer) {
 534   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 535   DCHECK(desktop_capturer);
 536
 537   if (stream_) {
 538     VLOG(1) << "Already added MediaStream. Aborting Setup.";
 539     return false;
 540   }
 541
 542   scoped_ptr<CastVideoCapturerAdapter> cast_video_capturer_adapter(
 543       new CastVideoCapturerAdapter(desktop_capturer.Pass()));
 544
 545   // Set video stream constraints.
 546   webrtc::FakeConstraints video_constraints;
 547   video_constraints.AddMandatory(
 548       webrtc::MediaConstraintsInterface::kMinFrameRate, kMinFramesPerSecond);
 549
 550   rtc::scoped_refptr<webrtc::VideoTrackInterface> video_track =
 551       peer_conn_factory_->CreateVideoTrack(
 552           kVideoLabel,
 553           peer_conn_factory_->CreateVideoSource(
 554               cast_video_capturer_adapter.release(), &video_constraints));
 555
 556   stream_ = peer_conn_factory_->CreateLocalMediaStream(kStreamLabel);
 557
 558   if (!stream_->AddTrack(video_track) ||
 559       !peer_connection_->AddStream(stream_, NULL)) {
 560     return false;
 561   }
 562
 563   VLOG(1) << "Setup video stream successfully.";
 564
 565   return true;
 566 }
 567
 568 void CastExtensionSession::PollPeerConnectionStats() {
 569   if (!connection_active()) {
 570     VLOG(1) << "Cannot poll stats while PeerConnection is inactive.";
 571   }
 572   rtc::scoped_refptr<webrtc::MediaStreamTrackInterface> video_track =
 573       stream_->FindVideoTrack(kVideoLabel);
 574   peer_connection_->GetStats(
 575       stats_observer_,
 576       video_track.release(),
 577       webrtc::PeerConnectionInterface::kStatsOutputLevelStandard);
 578 }
 579
 580 void CastExtensionSession::CleanupPeerConnection() {
 581   peer_connection_->Close();
 582   peer_connection_ = NULL;
 583   stream_ = NULL;
 584   peer_conn_factory_ = NULL;
 585   worker_thread_.Stop();
 586 }
 587
 588 bool CastExtensionSession::connection_active() const {
 589   return peer_connection_.get() != NULL;
 590 }
 591
 592 // webrtc::PeerConnectionObserver implementation -------------------------------
 593
 594 void CastExtensionSession::OnError() {
 595   VLOG(1) << "PeerConnectionObserver: an error occurred.";
 596 }
 597
 598 void CastExtensionSession::OnSignalingChange(
 599     webrtc::PeerConnectionInterface::SignalingState new_state) {
 600   VLOG(1) << "PeerConnectionObserver: SignalingState changed to:" << new_state;
 601 }
 602
 603 void CastExtensionSession::OnStateChange(
 604     webrtc::PeerConnectionObserver::StateType state_changed) {
 605   VLOG(1) << "PeerConnectionObserver: StateType changed to: " << state_changed;
 606 }
 607
 608 void CastExtensionSession::OnAddStream(webrtc::MediaStreamInterface* stream) {
 609   VLOG(1) << "PeerConnectionObserver: stream added: " << stream->label();
 610 }
 611
 612 void CastExtensionSession::OnRemoveStream(
 613     webrtc::MediaStreamInterface* stream) {
 614   VLOG(1) << "PeerConnectionObserver: stream removed: " << stream->label();
 615 }
 616
 617 void CastExtensionSession::OnDataChannel(
 618     webrtc::DataChannelInterface* data_channel) {
 619   VLOG(1) << "PeerConnectionObserver: data channel: " << data_channel->label();
 620 }
 621
 622 void CastExtensionSession::OnRenegotiationNeeded() {
 623   VLOG(1) << "PeerConnectionObserver: renegotiation needed.";
 624 }
 625
 626 void CastExtensionSession::OnIceConnectionChange(
 627     webrtc::PeerConnectionInterface::IceConnectionState new_state) {
 628   VLOG(1) << "PeerConnectionObserver: IceConnectionState changed to: "
 629           << new_state;
 630
 631   // TODO(aiguha): Maybe start timer only if enabled by command-line flag or
 632   // at a particular verbosity level.
 633   if (!stats_polling_timer_.IsRunning() &&
 634       new_state == webrtc::PeerConnectionInterface::kIceConnectionConnected) {
 635     stats_polling_timer_.Start(
 636         FROM_HERE,
 637         base::TimeDelta::FromSeconds(kStatsLogIntervalSec),
 638         this,
 639         &CastExtensionSession::PollPeerConnectionStats);
 640   }
 641 }
 642
 643 void CastExtensionSession::OnIceGatheringChange(
 644     webrtc::PeerConnectionInterface::IceGatheringState new_state) {
 645   VLOG(1) << "PeerConnectionObserver: IceGatheringState changed to: "
 646           << new_state;
 647 }
 648
 649 void CastExtensionSession::OnIceComplete() {
 650   VLOG(1) << "PeerConnectionObserver: all ICE candidates found.";
 651 }
 652
 653 void CastExtensionSession::OnIceCandidate(
 654     const webrtc::IceCandidateInterface* candidate) {
 655   std::string candidate_str;
 656   if (!candidate->ToString(&candidate_str)) {
 657     LOG(ERROR) << "PeerConnectionObserver: failed to serialize candidate.";
 658     return;
 659   }
 660   scoped_ptr<base::DictionaryValue> json(new base::DictionaryValue());
 661   json->SetString(kWebRtcSDPMid, candidate->sdp_mid());
 662   json->SetInteger(kWebRtcSDPMLineIndex, candidate->sdp_mline_index());
 663   json->SetString(kWebRtcCandidate, candidate_str);
 664   std::string json_str;
 665   if (!base::JSONWriter::Write(json.get(), &json_str)) {
 666     LOG(ERROR) << "Failed to serialize candidate message.";
 667     return;
 668   }
 669   SendMessageToClient(kSubjectNewCandidate, json_str);
 670 }
 671
 672 }  // namespace remoting