diff --git a/third_party_mods/libjingle/libjingle.gyp b/third_party_mods/libjingle/libjingle.gyp
index 003d400fd..3ad05d983 100644
--- a/third_party_mods/libjingle/libjingle.gyp
+++ b/third_party_mods/libjingle/libjingle.gyp
@@ -770,8 +770,8 @@
             }],
           ], #conditions             
           'sources': [
-            '<(libjingle_mods)/source/talk/app/webrtc_dev/mediastreamhandler_unittest.cc',
-            '<(libjingle_mods)/source/talk/app/webrtc_dev/mediastreamimpl_unittest.cc',           
+            '<(libjingle_mods)/source/talk/app/webrtc_dev/mediastream_unittest.cc',
+            '<(libjingle_mods)/source/talk/app/webrtc_dev/mediastreamhandler_unittest.cc',                       
             '<(libjingle_mods)/source/talk/app/webrtc_dev/peerconnection_unittest.cc',
             '<(libjingle_mods)/source/talk/app/webrtc_dev/peerconnection_unittests.cc',
             '<(libjingle_mods)/source/talk/app/webrtc_dev/peerconnectionimpl_unittest.cc',
diff --git a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastream_unittest.cc b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastream_unittest.cc
new file mode 100644
index 000000000..2c39e9ad4
--- /dev/null
+++ b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastream_unittest.cc
@@ -0,0 +1,439 @@
+/*
+ * libjingle
+ * Copyright 2011, 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,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "talk/app/webrtc_dev/mediastreamproxy.h"
+#include "talk/app/webrtc_dev/mediastreamtrackproxy.h"
+#include "talk/app/webrtc_dev/ref_count.h"
+#include "talk/base/scoped_ptr.h"
+#include "talk/base/thread.h"
+
+static const char kStreamLabel1[] = "local_stream_1";
+static const char kVideoTrackLabel[] = "dummy_video_cam_1";
+static const char kAudioTrackLabel[] = "dummy_microphone_1";
+
+using talk_base::scoped_refptr;
+using ::testing::Exactly;
+
+namespace {
+
+class ReadyStateMessageData : public talk_base::MessageData {
+ public:
+  ReadyStateMessageData(
+      webrtc::MediaStreamInterface* stream,
+      webrtc::MediaStreamInterface::ReadyState new_state)
+      : stream_(stream),
+        ready_state_(new_state) {
+  }
+
+  scoped_refptr<webrtc::MediaStreamInterface> stream_;
+  webrtc::MediaStreamInterface::ReadyState ready_state_;
+};
+
+class SsrcMessageData : public talk_base::MessageData {
+ public:
+  SsrcMessageData(
+      webrtc::MediaStreamTrackInterface* track,
+      uint32 ssrc)
+      : track_(track),
+        ssrc_(ssrc) {
+  }
+
+  scoped_refptr<webrtc::MediaStreamTrackInterface> track_;
+  uint32 ssrc_;
+};
+
+class TrackStateMessageData : public talk_base::MessageData {
+ public:
+  TrackStateMessageData(
+      webrtc::MediaStreamTrackInterface* track,
+      webrtc::MediaStreamTrackInterface::TrackState state)
+      : track_(track),
+        state_(state) {
+  }
+
+  scoped_refptr<webrtc::MediaStreamTrackInterface> track_;
+  webrtc::MediaStreamTrackInterface::TrackState state_;
+};
+
+}  // namespace anonymous
+
+namespace webrtc {
+
+// Helper class to test Observer.
+class MockObserver : public ObserverInterface {
+ public:
+  explicit MockObserver(talk_base::Thread* signaling_thread)
+      : signaling_thread_(signaling_thread) {
+  }
+
+  MOCK_METHOD0(DoOnChanged, void());
+  virtual void OnChanged() {
+    ASSERT_TRUE(talk_base::Thread::Current() == signaling_thread_);
+    DoOnChanged();
+  }
+ private:
+  talk_base::Thread* signaling_thread_;
+};
+
+class MockMediaStream: public LocalMediaStreamInterface {
+ public:
+  MockMediaStream(const std::string& label, talk_base::Thread* signaling_thread)
+      : stream_impl_(MediaStream::Create(label)),
+        signaling_thread_(signaling_thread) {
+  }
+  virtual void RegisterObserver(webrtc::ObserverInterface* observer) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    stream_impl_->RegisterObserver(observer);
+  }
+  virtual void UnregisterObserver(webrtc::ObserverInterface* observer) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    stream_impl_->UnregisterObserver(observer);
+  }
+  virtual std::string label() const {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->label();
+  }
+  virtual AudioTracks* audio_tracks() {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->audio_tracks();
+  }
+  virtual VideoTracks* video_tracks() {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->video_tracks();
+  }
+  virtual ReadyState ready_state() {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->ready_state();
+  }
+  virtual void set_ready_state(ReadyState state) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->set_ready_state(state);
+  }
+  virtual bool AddTrack(AudioTrackInterface* audio_track) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->AddTrack(audio_track);
+  }
+  virtual bool AddTrack(VideoTrackInterface* video_track) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return stream_impl_->AddTrack(video_track);
+  }
+
+ private:
+  scoped_refptr<MediaStream> stream_impl_;
+  talk_base::Thread* signaling_thread_;
+};
+
+template <class T>
+class MockMediaStreamTrack: public T {
+ public:
+  MockMediaStreamTrack(T* implementation,
+                       talk_base::Thread* signaling_thread)
+      : track_impl_(implementation),
+        signaling_thread_(signaling_thread) {
+  }
+  virtual void RegisterObserver(webrtc::ObserverInterface* observer) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    track_impl_->RegisterObserver(observer);
+  }
+  virtual void UnregisterObserver(webrtc::ObserverInterface* observer) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    track_impl_->UnregisterObserver(observer);
+  }
+  virtual const char* kind() const {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->kind();
+  }
+  virtual std::string label() const {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->label();
+  }
+  virtual uint32 ssrc() const {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->ssrc();
+  }
+  virtual bool enabled() const {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->enabled();
+  }
+  virtual MediaStreamTrackInterface::TrackState state() const {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->state();
+  }
+  virtual bool set_enabled(bool enabled) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->set_enabled(enabled);
+  }
+  virtual bool set_ssrc(uint32 ssrc) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->set_ssrc(ssrc);
+  }
+  virtual bool set_state(webrtc::MediaStreamTrackInterface::TrackState state) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->set_state(state);
+  }
+
+ protected:
+  scoped_refptr<T> track_impl_;
+  talk_base::Thread* signaling_thread_;
+};
+
+class MockLocalVideoTrack
+    : public MockMediaStreamTrack<LocalVideoTrackInterface> {
+ public:
+    MockLocalVideoTrack(LocalVideoTrackInterface* implementation,
+                        talk_base::Thread* signaling_thread)
+        : MockMediaStreamTrack<LocalVideoTrackInterface>(implementation,
+                                                         signaling_thread) {
+    }
+  virtual void SetRenderer(webrtc::VideoRendererWrapperInterface* renderer) {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    track_impl_->SetRenderer(renderer);
+  }
+  virtual VideoRendererWrapperInterface* GetRenderer() {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->GetRenderer();
+  }
+  virtual VideoCaptureModule* GetVideoCapture() {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->GetVideoCapture();
+  }
+};
+
+class MockLocalAudioTrack
+    : public MockMediaStreamTrack<LocalAudioTrackInterface> {
+ public:
+  MockLocalAudioTrack(LocalAudioTrackInterface* implementation,
+                      talk_base::Thread* signaling_thread)
+    : MockMediaStreamTrack<LocalAudioTrackInterface>(implementation,
+                                                     signaling_thread) {
+  }
+
+  virtual AudioDeviceModule* GetAudioDevice() {
+    EXPECT_EQ(talk_base::Thread::Current(), signaling_thread_);
+    return track_impl_->GetAudioDevice();
+  }
+};
+
+class MediaStreamTest: public testing::Test,
+                       public talk_base::MessageHandler {
+ protected:
+  virtual void SetUp() {
+    signaling_thread_ .reset(new talk_base::Thread());
+    ASSERT_TRUE(signaling_thread_->Start());
+
+    std::string label(kStreamLabel1);
+    // Create a stream proxy object that uses our mocked
+    // version of a LocalMediaStream.
+    scoped_refptr<MockMediaStream> mock_stream(
+        new talk_base::RefCount<MockMediaStream>(label,
+                                                 signaling_thread_.get()));
+    stream_ = MediaStreamProxy::Create(label, signaling_thread_.get(),
+                                       mock_stream);
+    ASSERT_TRUE(stream_.get());
+    EXPECT_EQ(label, stream_->label());
+    EXPECT_EQ(MediaStreamInterface::kInitializing, stream_->ready_state());
+
+    // Create a video track proxy object that uses our mocked
+    // version of a LocalVideoTrack
+    scoped_refptr<VideoTrack> video_track_impl(
+        VideoTrack::CreateLocal(kVideoTrackLabel, NULL));
+    scoped_refptr<MockLocalVideoTrack> mock_videotrack(
+        new talk_base::RefCount<MockLocalVideoTrack>(video_track_impl,
+                                                     signaling_thread_.get()));
+    video_track_ = VideoTrackProxy::CreateLocal(mock_videotrack,
+                                                signaling_thread_.get());
+
+    ASSERT_TRUE(video_track_.get());
+    EXPECT_EQ(MediaStreamTrackInterface::kInitializing, video_track_->state());
+    EXPECT_EQ(0u, video_track_->ssrc());
+
+    // Create an audio track proxy object that uses our mocked
+    // version of a LocalAudioTrack
+    scoped_refptr<AudioTrack> audio_track_impl(
+        AudioTrack::CreateLocal(kAudioTrackLabel, NULL));
+    scoped_refptr<MockLocalAudioTrack> mock_audiotrack(
+        new talk_base::RefCount<MockLocalAudioTrack>(audio_track_impl,
+                                                     signaling_thread_.get()));
+    audio_track_ = AudioTrackProxy::CreateLocal(mock_audiotrack,
+                                                signaling_thread_.get());
+
+    ASSERT_TRUE(audio_track_.get());
+    EXPECT_EQ(MediaStreamTrackInterface::kInitializing, audio_track_->state());
+    EXPECT_EQ(0u, audio_track_->ssrc());
+  }
+
+  enum {
+    MSG_SET_READYSTATE,
+    MSG_SET_SSRC,
+    MSG_SET_TRACKSTATE,
+  };
+
+  // Set the ready state on the signaling thread.
+  // State can only be changed on the signaling thread.
+  void SetReadyState(MediaStreamInterface* stream,
+                     MediaStreamInterface::ReadyState new_state) {
+    ReadyStateMessageData state(stream, new_state);
+    signaling_thread_->Send(this, MSG_SET_READYSTATE, &state);
+  }
+
+  // Set the track state on the signaling thread.
+  // State can only be changed on the signaling thread.
+  void SetTrackState(MediaStreamTrackInterface* track,
+                     MediaStreamTrackInterface::TrackState new_state) {
+    TrackStateMessageData state(track, new_state);
+    signaling_thread_->Send(this, MSG_SET_TRACKSTATE, &state);
+  }
+
+  // Set the ssrc on a track on the signaling thread.
+  // Ssrc can only be changed on the signaling thread.
+  void SetSsrc(MediaStreamTrackInterface* track,
+               uint32 new_ssrc) {
+    SsrcMessageData ssrc(track, new_ssrc);
+    signaling_thread_->Send(this, MSG_SET_SSRC, &ssrc);
+  }
+
+  talk_base::scoped_ptr<talk_base::Thread> signaling_thread_;
+  scoped_refptr<LocalMediaStreamInterface> stream_;
+  scoped_refptr<LocalVideoTrackInterface> video_track_;
+  scoped_refptr<LocalAudioTrackInterface> audio_track_;
+
+ private:
+  // Implements talk_base::MessageHandler.
+  virtual void OnMessage(talk_base::Message* msg) {
+    switch (msg->message_id) {
+      case MSG_SET_READYSTATE: {
+        ReadyStateMessageData* state =
+            static_cast<ReadyStateMessageData*>(msg->pdata);
+        state->stream_->set_ready_state(state->ready_state_);
+        break;
+      }
+      case MSG_SET_SSRC: {
+        SsrcMessageData* ssrc =
+            static_cast<SsrcMessageData*>(msg->pdata);
+        ssrc->track_->set_ssrc(ssrc->ssrc_);
+        break;
+      }
+      case MSG_SET_TRACKSTATE: {
+        TrackStateMessageData* state =
+            static_cast<TrackStateMessageData*>(msg->pdata);
+        state->track_->set_state(state->state_);
+        break;
+      }
+      default:
+        break;
+    }
+  }
+};
+
+TEST_F(MediaStreamTest, CreateLocalStream) {
+  EXPECT_TRUE(stream_->AddTrack(video_track_));
+  EXPECT_TRUE(stream_->AddTrack(audio_track_));
+
+  ASSERT_EQ(1u, stream_->video_tracks()->count());
+  ASSERT_EQ(1u, stream_->audio_tracks()->count());
+
+  // Verify the video track.
+  scoped_refptr<webrtc::MediaStreamTrackInterface> track(
+      stream_->video_tracks()->at(0));
+  EXPECT_EQ(0, track->label().compare(kVideoTrackLabel));
+  EXPECT_TRUE(track->enabled());
+
+  // Verify the audio track.
+  track = stream_->audio_tracks()->at(0);
+  EXPECT_EQ(0, track->label().compare(kAudioTrackLabel));
+  EXPECT_TRUE(track->enabled());
+}
+
+TEST_F(MediaStreamTest, ChangeStreamState) {
+  MockObserver observer(signaling_thread_.get());
+  stream_->RegisterObserver(&observer);
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+  SetReadyState(stream_, MediaStreamInterface::kLive);
+
+  EXPECT_EQ(MediaStreamInterface::kLive, stream_->ready_state());
+  // It should not be possible to add
+  // streams when the state has changed to live.
+  EXPECT_FALSE(stream_->AddTrack(audio_track_));
+  EXPECT_EQ(0u, stream_->audio_tracks()->count());
+}
+
+TEST_F(MediaStreamTest, ChangeVideoTrack) {
+  MockObserver observer(signaling_thread_.get());
+  video_track_->RegisterObserver(&observer);
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+
+  video_track_->set_enabled(false);
+  EXPECT_FALSE(video_track_->state());
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+  SetSsrc(video_track_, 255);
+  EXPECT_EQ(255u, video_track_->ssrc());
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+  SetTrackState(video_track_, MediaStreamTrackInterface::kLive);
+  EXPECT_EQ(MediaStreamTrackInterface::kLive, video_track_->state());
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+  scoped_refptr<VideoRendererWrapperInterface> renderer(
+      CreateVideoRenderer(NULL));
+  video_track_->SetRenderer(renderer.get());
+  EXPECT_TRUE(renderer.get() == video_track_->GetRenderer());
+}
+
+TEST_F(MediaStreamTest, ChangeAudioTrack) {
+  MockObserver observer(signaling_thread_.get());
+  audio_track_->RegisterObserver(&observer);
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+
+  audio_track_->set_enabled(false);
+  EXPECT_FALSE(audio_track_->enabled());
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+  SetSsrc(audio_track_, 255);
+  EXPECT_EQ(255u, audio_track_->ssrc());
+
+  EXPECT_CALL(observer, DoOnChanged())
+      .Times(Exactly(1));
+  SetTrackState(audio_track_, MediaStreamTrackInterface::kLive);
+  EXPECT_EQ(MediaStreamTrackInterface::kLive, audio_track_->state());
+}
+
+}  // namespace webrtc
diff --git a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.cc b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.cc
index 7f02fd155..f49cd26c5 100644
--- a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.cc
+++ b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.cc
@@ -32,13 +32,13 @@
 namespace {
 
 enum {
-  MSG_REGISTER_OBSERVER = 1,
+  MSG_SET_TRACKLIST_IMPLEMENTATION = 1,
+  MSG_REGISTER_OBSERVER,
   MSG_UNREGISTER_OBSERVER,
   MSG_LABEL,
   MSG_ADD_AUDIO_TRACK,
   MSG_ADD_VIDEO_TRACK,
   MSG_READY_STATE,
-  MSG_SET_READY_STATE,
   MSG_COUNT,
   MSG_AT
 };
@@ -78,6 +78,12 @@ class MediaStreamTrackAtMessageData : public talk_base::MessageData {
   talk_base::scoped_refptr<TrackType> track_;
 };
 
+class MediaStreamTrackListsMessageData : public talk_base::MessageData {
+ public:
+  talk_base::scoped_refptr<webrtc::AudioTracks> audio_tracks_;
+  talk_base::scoped_refptr<webrtc::VideoTracks> video_tracks_;
+};
+
 }  // namespace anonymous
 
 namespace webrtc {
@@ -87,22 +93,43 @@ talk_base::scoped_refptr<MediaStreamProxy> MediaStreamProxy::Create(
     talk_base::Thread* signaling_thread) {
   ASSERT(signaling_thread);
   talk_base::RefCount<MediaStreamProxy>* stream =
-      new talk_base::RefCount<MediaStreamProxy>(label, signaling_thread);
+      new talk_base::RefCount<MediaStreamProxy>(
+          label, signaling_thread,
+          reinterpret_cast<LocalMediaStreamInterface*>(NULL));
+  return stream;
+}
+
+talk_base::scoped_refptr<MediaStreamProxy> MediaStreamProxy::Create(
+    const std::string& label,
+    talk_base::Thread* signaling_thread,
+    LocalMediaStreamInterface* media_stream_impl) {
+  ASSERT(signaling_thread);
+  ASSERT(media_stream_impl);
+  talk_base::RefCount<MediaStreamProxy>* stream =
+      new talk_base::RefCount<MediaStreamProxy>(label, signaling_thread,
+                                                media_stream_impl);
   return stream;
 }
 
 MediaStreamProxy::MediaStreamProxy(const std::string& label,
-                                   talk_base::Thread* signaling_thread)
+                                   talk_base::Thread* signaling_thread,
+                                   LocalMediaStreamInterface* media_stream_impl)
     : signaling_thread_(signaling_thread),
-      media_stream_impl_(MediaStream::Create(label)),
+      media_stream_impl_(media_stream_impl),
       audio_tracks_(new talk_base::RefCount<
-                    MediaStreamTrackListProxy<AudioTrackInterface> >(
-                    media_stream_impl_->audio_tracks(),
-                    signaling_thread_)),
+                        MediaStreamTrackListProxy<AudioTrackInterface> >(
+                              signaling_thread_)),
       video_tracks_(new talk_base::RefCount<
-                    MediaStreamTrackListProxy<VideoTrackInterface> >(
-                    media_stream_impl_->video_tracks(),
-                    signaling_thread_)) {
+                        MediaStreamTrackListProxy<VideoTrackInterface> >(
+                            signaling_thread_)) {
+  if (media_stream_impl_ == NULL) {
+    media_stream_impl_ = MediaStream::Create(label);
+  }
+
+  MediaStreamTrackListsMessageData tracklists;
+  Send(MSG_SET_TRACKLIST_IMPLEMENTATION, &tracklists);
+  audio_tracks_->SetImplementation(tracklists.audio_tracks_);
+  video_tracks_->SetImplementation(tracklists.video_tracks_);
 }
 
 std::string MediaStreamProxy::label() const {
@@ -127,8 +154,8 @@ MediaStreamInterface::ReadyState MediaStreamProxy::ready_state() {
 void MediaStreamProxy::set_ready_state(
     MediaStreamInterface::ReadyState new_state) {
   if (!signaling_thread_->IsCurrent()) {
-    ReadyStateMessageData msg(MediaStreamInterface::kInitializing);
-    Send(MSG_SET_READY_STATE, &msg);
+    // State should only be allowed to be changed from the signaling thread.
+    ASSERT(!"Not Allowed!");
     return;
   }
   media_stream_impl_->set_ready_state(new_state);
@@ -179,6 +206,13 @@ void MediaStreamProxy::Send(uint32 id, talk_base::MessageData* data) const {
 void MediaStreamProxy::OnMessage(talk_base::Message* msg) {
   talk_base::MessageData* data = msg->pdata;
   switch (msg->message_id) {
+    case MSG_SET_TRACKLIST_IMPLEMENTATION: {
+      MediaStreamTrackListsMessageData* lists =
+          static_cast<MediaStreamTrackListsMessageData*>(data);
+      lists->audio_tracks_ = media_stream_impl_->audio_tracks();
+      lists->video_tracks_ = media_stream_impl_->video_tracks();
+      break;
+    }
     case MSG_REGISTER_OBSERVER: {
       ObserverMessageData* observer = static_cast<ObserverMessageData*>(data);
       media_stream_impl_->RegisterObserver(observer->data());
@@ -211,11 +245,6 @@ void MediaStreamProxy::OnMessage(talk_base::Message* msg) {
       state->data() = media_stream_impl_->ready_state();
       break;
     }
-    case MSG_SET_READY_STATE: {
-      ReadyStateMessageData* state = static_cast<ReadyStateMessageData*>(data);
-      media_stream_impl_->set_ready_state(state->data());
-      break;
-    }
     default:
       ASSERT(!"Not Implemented!");
       break;
@@ -224,10 +253,14 @@ void MediaStreamProxy::OnMessage(talk_base::Message* msg) {
 
 template <class T>
 MediaStreamProxy::MediaStreamTrackListProxy<T>::MediaStreamTrackListProxy(
-    MediaStreamTrackListInterface<T>* track_list,
     talk_base::Thread* signaling_thread)
-    :  track_list_(track_list),
-       signaling_thread_(signaling_thread) {
+    : signaling_thread_(signaling_thread) {
+}
+
+template <class T>
+void MediaStreamProxy::MediaStreamTrackListProxy<T>::SetImplementation(
+    MediaStreamTrackListInterface<T>* track_list) {
+  track_list_ = track_list;
 }
 
 template <class T>
diff --git a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.h b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.h
index 8ef1dfba1..c06b31011 100644
--- a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.h
+++ b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamproxy.h
@@ -35,6 +35,7 @@
 #include "talk/base/thread.h"
 
 namespace webrtc {
+using talk_base::scoped_refptr;
 
 // MediaStreamProxy is a proxy for the MediaStream interface. The purpose is
 // to make sure MediaStreamImpl is only accessed from the signaling thread.
@@ -42,34 +43,19 @@ namespace webrtc {
 class MediaStreamProxy : public LocalMediaStreamInterface,
                          public talk_base::MessageHandler {
  public:
-  template <class T>
-  class MediaStreamTrackListProxy : public MediaStreamTrackListInterface<T>,
-                                    public talk_base::MessageHandler {
-   public:
-    MediaStreamTrackListProxy(MediaStreamTrackListInterface<T>* track_list,
-                              talk_base::Thread* signaling_thread);
-    virtual size_t count();
-    virtual T* at(size_t index);
-
-   private:
-    void Send(uint32 id, talk_base::MessageData* data) const;
-    void OnMessage(talk_base::Message* msg);
-
-    talk_base::scoped_refptr<MediaStreamTrackListInterface<T> > track_list_;
-    mutable talk_base::Thread* signaling_thread_;
-  };
-
-  static talk_base::scoped_refptr<MediaStreamProxy> Create(
+  static scoped_refptr<MediaStreamProxy> Create(
       const std::string& label,
       talk_base::Thread* signaling_thread);
 
+  static scoped_refptr<MediaStreamProxy> Create(
+      const std::string& label,
+      talk_base::Thread* signaling_thread,
+      LocalMediaStreamInterface* media_stream_impl);
+
   // Implement LocalStream.
   virtual bool AddTrack(AudioTrackInterface* track);
   virtual bool AddTrack(VideoTrackInterface* track);
 
-  // This will be used when Tracks are created internally.
-  bool AddTrack(MediaStreamTrackInterface* track);
-
   // Implement MediaStream.
   virtual std::string label() const;
   virtual AudioTracks* audio_tracks() {
@@ -86,17 +72,38 @@ class MediaStreamProxy : public LocalMediaStreamInterface,
   virtual void UnregisterObserver(ObserverInterface* observer);
 
  protected:
-  explicit MediaStreamProxy(const std::string& label,
-                            talk_base::Thread* signaling_thread);
+  MediaStreamProxy(const std::string& label,
+                   talk_base::Thread* signaling_thread,
+                   LocalMediaStreamInterface* media_stream_impl);
+
+  template <class T>
+  class MediaStreamTrackListProxy : public MediaStreamTrackListInterface<T>,
+                                    public talk_base::MessageHandler {
+   public:
+    MediaStreamTrackListProxy(talk_base::Thread* signaling_thread);
+
+    void SetImplementation(MediaStreamTrackListInterface<T>* track_list);
+    virtual size_t count();
+    virtual T* at(size_t index);
+
+   private:
+    void Send(uint32 id, talk_base::MessageData* data) const;
+    void OnMessage(talk_base::Message* msg);
+
+    talk_base::scoped_refptr<MediaStreamTrackListInterface<T> > track_list_;
+    mutable talk_base::Thread* signaling_thread_;
+  };
+  typedef MediaStreamTrackListProxy<AudioTrackInterface> AudioTrackListProxy;
+  typedef MediaStreamTrackListProxy<VideoTrackInterface> VideoTrackListProxy;
 
   void Send(uint32 id, talk_base::MessageData* data) const;
-  // Implement MessageHandler
+  // Implement MessageHandler.
   virtual void OnMessage(talk_base::Message* msg);
 
   mutable talk_base::Thread* signaling_thread_;
-  talk_base::scoped_refptr<MediaStream> media_stream_impl_;
-  talk_base::scoped_refptr<AudioTracks> audio_tracks_;
-  talk_base::scoped_refptr<VideoTracks> video_tracks_;
+  scoped_refptr<LocalMediaStreamInterface> media_stream_impl_;
+  scoped_refptr<AudioTrackListProxy> audio_tracks_;
+  scoped_refptr<VideoTrackListProxy> video_tracks_;
 };
 
 }  // namespace webrtc
diff --git a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.cc b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.cc
index 200bd227d..30764d878 100644
--- a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.cc
+++ b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.cc
@@ -238,24 +238,29 @@ bool MediaStreamTrackProxy<T>::HandleMessage(talk_base::Message* msg) {
   }
 }
 
-AudioTrackProxy::AudioTrackProxy(
-    const std::string& label,
-    uint32 ssrc,
-    talk_base::Thread* signaling_thread)
+AudioTrackProxy::AudioTrackProxy(const std::string& label,
+                                 uint32 ssrc,
+                                 talk_base::Thread* signaling_thread)
     : MediaStreamTrackProxy<LocalAudioTrackInterface>(signaling_thread),
       audio_track_(AudioTrack::CreateRemote(label, ssrc)) {
   Init(audio_track_);
 }
 
-AudioTrackProxy::AudioTrackProxy(
-    const std::string& label,
-    AudioDeviceModule* audio_device,
-    talk_base::Thread* signaling_thread)
+AudioTrackProxy::AudioTrackProxy(const std::string& label,
+                                 AudioDeviceModule* audio_device,
+                                 talk_base::Thread* signaling_thread)
     : MediaStreamTrackProxy<LocalAudioTrackInterface>(signaling_thread),
       audio_track_(AudioTrack::CreateLocal(label, audio_device)) {
   Init(audio_track_);
 }
 
+AudioTrackProxy::AudioTrackProxy(LocalAudioTrackInterface* implementation,
+                                 talk_base::Thread* signaling_thread)
+    : MediaStreamTrackProxy<LocalAudioTrackInterface>(signaling_thread),
+      audio_track_(implementation) {
+  Init(audio_track_);
+}
+
 talk_base::scoped_refptr<AudioTrackInterface> AudioTrackProxy::CreateRemote(
     const std::string& label,
     uint32 ssrc,
@@ -279,6 +284,16 @@ talk_base::scoped_refptr<LocalAudioTrackInterface> AudioTrackProxy::CreateLocal(
   return track;
 }
 
+talk_base::scoped_refptr<LocalAudioTrackInterface> AudioTrackProxy::CreateLocal(
+    LocalAudioTrackInterface* implementation,
+    talk_base::Thread* signaling_thread) {
+  ASSERT(signaling_thread);
+  talk_base::RefCount<AudioTrackProxy>* track =
+      new talk_base::RefCount<AudioTrackProxy>(implementation,
+                                               signaling_thread);
+  return track;
+}
+
 AudioDeviceModule* AudioTrackProxy::GetAudioDevice() {
   if (!signaling_thread_->IsCurrent()) {
     AudioDeviceMessageData msg;
@@ -300,24 +315,29 @@ void AudioTrackProxy::OnMessage(talk_base::Message* msg) {
   }
 }
 
-VideoTrackProxy::VideoTrackProxy(
-    const std::string& label,
-    uint32 ssrc,
-    talk_base::Thread* signaling_thread)
+VideoTrackProxy::VideoTrackProxy(const std::string& label,
+                                 uint32 ssrc,
+                                 talk_base::Thread* signaling_thread)
     : MediaStreamTrackProxy<LocalVideoTrackInterface>(signaling_thread),
       video_track_(VideoTrack::CreateRemote(label, ssrc)) {
   Init(video_track_);
 }
 
-VideoTrackProxy::VideoTrackProxy(
-    const std::string& label,
-    VideoCaptureModule* video_device,
-    talk_base::Thread* signaling_thread)
+VideoTrackProxy::VideoTrackProxy(const std::string& label,
+                                 VideoCaptureModule* video_device,
+                                 talk_base::Thread* signaling_thread)
     : MediaStreamTrackProxy<LocalVideoTrackInterface>(signaling_thread),
       video_track_(VideoTrack::CreateLocal(label, video_device)) {
   Init(video_track_);
 }
 
+VideoTrackProxy::VideoTrackProxy(LocalVideoTrackInterface* implementation,
+                                 talk_base::Thread* signaling_thread)
+    : MediaStreamTrackProxy<LocalVideoTrackInterface>(signaling_thread),
+      video_track_(implementation) {
+  Init(video_track_);
+}
+
 talk_base::scoped_refptr<VideoTrackInterface> VideoTrackProxy::CreateRemote(
     const std::string& label,
     uint32 ssrc,
@@ -340,6 +360,16 @@ talk_base::scoped_refptr<LocalVideoTrackInterface> VideoTrackProxy::CreateLocal(
   return track;
 }
 
+talk_base::scoped_refptr<LocalVideoTrackInterface> VideoTrackProxy::CreateLocal(
+    LocalVideoTrackInterface* implementation,
+    talk_base::Thread* signaling_thread) {
+  ASSERT(signaling_thread);
+  talk_base::RefCount<VideoTrackProxy>* track =
+      new talk_base::RefCount<VideoTrackProxy>(implementation,
+                                               signaling_thread);
+  return track;
+}
+
 VideoCaptureModule* VideoTrackProxy::GetVideoCapture() {
   if (!signaling_thread_->IsCurrent()) {
     VideoDeviceMessageData msg;
diff --git a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.h b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.h
index d9f2c0cce..b2dc78fab 100644
--- a/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.h
+++ b/third_party_mods/libjingle/source/talk/app/webrtc_dev/mediastreamtrackproxy.h
@@ -85,6 +85,9 @@ class AudioTrackProxy : public MediaStreamTrackProxy<LocalAudioTrackInterface> {
       const std::string& label,
       AudioDeviceModule* audio_device,
       talk_base::Thread* signaling_thread);
+  static talk_base::scoped_refptr<LocalAudioTrackInterface> CreateLocal(
+      LocalAudioTrackInterface* implementation,
+      talk_base::Thread* signaling_thread);
 
   virtual AudioDeviceModule* GetAudioDevice();
 
@@ -95,10 +98,12 @@ class AudioTrackProxy : public MediaStreamTrackProxy<LocalAudioTrackInterface> {
   AudioTrackProxy(const std::string& label,
                   AudioDeviceModule* audio_device,
                   talk_base::Thread* signaling_thread);
+  AudioTrackProxy(LocalAudioTrackInterface* implementation,
+                  talk_base::Thread* signaling_thread);
   // Implement MessageHandler
   virtual void OnMessage(talk_base::Message* msg);
 
-  talk_base::scoped_refptr<AudioTrack> audio_track_;
+  talk_base::scoped_refptr<LocalAudioTrackInterface> audio_track_;
 };
 
 // VideoTrackProxy is a proxy for the VideoTrackInterface and
@@ -115,6 +120,9 @@ class VideoTrackProxy : public MediaStreamTrackProxy<LocalVideoTrackInterface> {
       const std::string& label,
       VideoCaptureModule* video_device,
       talk_base::Thread* signaling_thread);
+  static talk_base::scoped_refptr<LocalVideoTrackInterface> CreateLocal(
+      LocalVideoTrackInterface* implementation,
+      talk_base::Thread* signaling_thread);
 
   virtual VideoCaptureModule* GetVideoCapture();
   virtual void SetRenderer(VideoRendererWrapperInterface* renderer);
@@ -127,10 +135,13 @@ class VideoTrackProxy : public MediaStreamTrackProxy<LocalVideoTrackInterface> {
   VideoTrackProxy(const std::string& label,
                   VideoCaptureModule* video_device,
                   talk_base::Thread* signaling_thread);
+  VideoTrackProxy(LocalVideoTrackInterface* implementation,
+                  talk_base::Thread* signaling_thread);
+
   // Implement MessageHandler
   virtual void OnMessage(talk_base::Message* msg);
 
-  talk_base::scoped_refptr<VideoTrack> video_track_;
+  talk_base::scoped_refptr<LocalVideoTrackInterface> video_track_;
 };
 
 }  // namespace webrtc