Get rid of unnecessary Terminate() method and worker_thread_ from WebRtcVideoEngine2

BUG=
R=pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/51879004

Cr-Commit-Position: refs/heads/master@{#9258}
diff --git a/talk/media/base/fakemediaengine.h b/talk/media/base/fakemediaengine.h
index 04ab777..70f89c6 100644
--- a/talk/media/base/fakemediaengine.h
+++ b/talk/media/base/fakemediaengine.h
@@ -711,9 +711,6 @@
       : loglevel_(-1),
         options_changed_(false),
         fail_create_channel_(false) {}
-  bool Init(rtc::Thread* worker_thread) { return true; }
-  void Terminate() {}
-
   void SetLogging(int level, const char* filter) {
     loglevel_ = level;
     logfilter_ = filter;
@@ -751,6 +748,8 @@
     // sanity checks against that.
     codecs_.push_back(AudioCodec(101, "fake_audio_codec", 0, 0, 1, 0));
   }
+  bool Init(rtc::Thread* worker_thread) { return true; }
+  void Terminate() {}
   int GetCapabilities() { return AUDIO_SEND | AUDIO_RECV; }
   AudioOptions GetAudioOptions() const {
     return options_;
@@ -861,6 +860,7 @@
     // sanity checks against that.
     codecs_.push_back(VideoCodec(0, "fake_video_codec", 0, 0, 0, 0));
   }
+  void Init() {}
   bool GetOptions(VideoOptions* options) const {
     *options = options_;
     return true;
diff --git a/talk/media/base/mediaengine.h b/talk/media/base/mediaengine.h
index f4706e9..439622c 100644
--- a/talk/media/base/mediaengine.h
+++ b/talk/media/base/mediaengine.h
@@ -168,14 +168,10 @@
   virtual bool Init(rtc::Thread* worker_thread) {
     if (!voice_.Init(worker_thread))
       return false;
-    if (!video_.Init(worker_thread)) {
-      voice_.Terminate();
-      return false;
-    }
+    video_.Init();
     return true;
   }
   virtual void Terminate() {
-    video_.Terminate();
     voice_.Terminate();
   }
 
diff --git a/talk/media/base/videoengine_unittest.h b/talk/media/base/videoengine_unittest.h
index 90db020..e4d2829 100644
--- a/talk/media/base/videoengine_unittest.h
+++ b/talk/media/base/videoengine_unittest.h
@@ -496,7 +496,7 @@
 
   virtual void SetUp() {
     cricket::Device device("test", "device");
-    EXPECT_TRUE(engine_.Init(rtc::Thread::Current()));
+    engine_.Init();
     channel_.reset(engine_.CreateChannel(cricket::VideoOptions(), NULL));
     EXPECT_TRUE(channel_.get() != NULL);
     ConnectVideoChannelError();
@@ -551,7 +551,6 @@
   }
   virtual void TearDown() {
     channel_.reset();
-    engine_.Terminate();
   }
   void ConnectVideoChannelError() {
     channel_->SignalMediaError.connect(this,
diff --git a/talk/media/webrtc/webrtcvideoengine2.cc b/talk/media/webrtc/webrtcvideoengine2.cc
index 7d8cc02..8daedf8 100644
--- a/talk/media/webrtc/webrtcvideoengine2.cc
+++ b/talk/media/webrtc/webrtcvideoengine2.cc
@@ -530,8 +530,7 @@
 }
 
 WebRtcVideoEngine2::WebRtcVideoEngine2(WebRtcVoiceEngine* voice_engine)
-    : worker_thread_(NULL),
-      voice_engine_(voice_engine),
+    : voice_engine_(voice_engine),
       initialized_(false),
       call_factory_(&default_call_factory_),
       external_decoder_factory_(NULL),
@@ -551,10 +550,6 @@
 
 WebRtcVideoEngine2::~WebRtcVideoEngine2() {
   LOG(LS_INFO) << "WebRtcVideoEngine2::~WebRtcVideoEngine2";
-
-  if (initialized_) {
-    Terminate();
-  }
 }
 
 void WebRtcVideoEngine2::SetCallFactory(WebRtcCallFactory* call_factory) {
@@ -562,19 +557,9 @@
   call_factory_ = call_factory;
 }
 
-bool WebRtcVideoEngine2::Init(rtc::Thread* worker_thread) {
+void WebRtcVideoEngine2::Init() {
   LOG(LS_INFO) << "WebRtcVideoEngine2::Init";
-  worker_thread_ = worker_thread;
-  DCHECK(worker_thread_ != NULL);
-
   initialized_ = true;
-  return true;
-}
-
-void WebRtcVideoEngine2::Terminate() {
-  LOG(LS_INFO) << "WebRtcVideoEngine2::Terminate";
-
-  initialized_ = false;
 }
 
 int WebRtcVideoEngine2::GetCapabilities() { return VIDEO_RECV | VIDEO_SEND; }
diff --git a/talk/media/webrtc/webrtcvideoengine2.h b/talk/media/webrtc/webrtcvideoengine2.h
index 5897309..4edb232 100644
--- a/talk/media/webrtc/webrtcvideoengine2.h
+++ b/talk/media/webrtc/webrtcvideoengine2.h
@@ -123,8 +123,7 @@
   void SetCallFactory(WebRtcCallFactory* call_factory);
 
   // Basic video engine implementation.
-  bool Init(rtc::Thread* worker_thread);
-  void Terminate();
+  void Init();
 
   int GetCapabilities();
   bool SetDefaultEncoderConfig(const VideoEncoderConfig& config);
@@ -158,7 +157,6 @@
  private:
   std::vector<VideoCodec> GetSupportedCodecs() const;
 
-  rtc::Thread* worker_thread_;
   WebRtcVoiceEngine* voice_engine_;
   std::vector<VideoCodec> video_codecs_;
   std::vector<RtpHeaderExtension> rtp_header_extensions_;
diff --git a/talk/media/webrtc/webrtcvideoengine2_unittest.cc b/talk/media/webrtc/webrtcvideoengine2_unittest.cc
index 4cffada..505be9e 100644
--- a/talk/media/webrtc/webrtcvideoengine2_unittest.cc
+++ b/talk/media/webrtc/webrtcvideoengine2_unittest.cc
@@ -173,9 +173,8 @@
 TEST_F(WebRtcVideoEngine2VoiceTest, ConfiguresAvSyncForFirstReceiveChannel) {
   FakeCallFactory call_factory;
   engine_.SetCallFactory(&call_factory);
-
   voice_engine_.Init(rtc::Thread::Current());
-  engine_.Init(rtc::Thread::Current());
+  engine_.Init();
 
   rtc::scoped_ptr<VoiceMediaChannel> voice_channel(
       voice_engine_.CreateChannel());
@@ -386,7 +385,7 @@
 }
 
 TEST_F(WebRtcVideoEngine2Test, SetSendFailsBeforeSettingCodecs) {
-  engine_.Init(rtc::Thread::Current());
+  engine_.Init();
   rtc::scoped_ptr<VideoMediaChannel> channel(
       engine_.CreateChannel(cricket::VideoOptions(), NULL));
 
@@ -399,7 +398,7 @@
 }
 
 TEST_F(WebRtcVideoEngine2Test, GetStatsWithoutSendCodecsSetDoesNotCrash) {
-  engine_.Init(rtc::Thread::Current());
+  engine_.Init();
   rtc::scoped_ptr<VideoMediaChannel> channel(
       engine_.CreateChannel(cricket::VideoOptions(), NULL));
   EXPECT_TRUE(channel->AddSendStream(StreamParams::CreateLegacy(123)));
@@ -461,7 +460,7 @@
     cricket::WebRtcVideoEncoderFactory* encoder_factory,
     const std::vector<VideoCodec>& codecs) {
   engine_.SetExternalEncoderFactory(encoder_factory);
-  engine_.Init(rtc::Thread::Current());
+  engine_.Init();
 
   VideoMediaChannel* channel =
       engine_.CreateChannel(cricket::VideoOptions(), NULL);
@@ -474,7 +473,7 @@
     cricket::WebRtcVideoDecoderFactory* decoder_factory,
     const std::vector<VideoCodec>& codecs) {
   engine_.SetExternalDecoderFactory(decoder_factory);
-  engine_.Init(rtc::Thread::Current());
+  engine_.Init();
 
   VideoMediaChannel* channel =
       engine_.CreateChannel(cricket::VideoOptions(), NULL);
@@ -623,8 +622,7 @@
   cricket::FakeWebRtcVideoEncoderFactory encoder_factory;
   encoder_factory.AddSupportedVideoCodecType(webrtc::kVideoCodecH264, "H264");
   engine_.SetExternalEncoderFactory(&encoder_factory);
-
-  engine_.Init(rtc::Thread::Current());
+  engine_.Init();
 
   std::vector<cricket::VideoCodec> codecs(engine_.codecs());
   ASSERT_GE(codecs.size(), 2u);
@@ -822,7 +820,7 @@
   WebRtcVideoChannel2Test() : fake_call_(NULL), last_ssrc_(0) {}
   void SetUp() override {
     engine_.SetCallFactory(this);
-    engine_.Init(rtc::Thread::Current());
+    engine_.Init();
     channel_.reset(engine_.CreateChannel(cricket::VideoOptions(), NULL));
     ASSERT_TRUE(fake_call_ != NULL) << "Call not created through factory.";
     last_ssrc_ = 123;
@@ -1586,8 +1584,6 @@
   void TearDown() override {
     // Remove references to encoder_factory_ since this will be destroyed
     // before channel_ and engine_.
-    engine_.Terminate();
-    engine_.SetExternalEncoderFactory(nullptr);
     ASSERT_TRUE(channel_->SetSendCodecs(engine_.codecs()));
   }
 
@@ -2567,7 +2563,7 @@
 
   void SetUp() override {
     engine_.SetCallFactory(this);
-    engine_.Init(rtc::Thread::Current());
+    engine_.Init();
     channel_.reset(engine_.CreateChannel(VideoOptions(), NULL));
     ASSERT_TRUE(fake_call_ != NULL) << "Call not created through factory.";
     last_ssrc_ = 123;