[Cast] Cleanup: Remove TransportXXXXXSender, an unnecessary layer of indirection.

media/cast/transport/cast_transport_sender_impl.cc

Index: media/cast/transport/cast_transport_sender_impl.cc
diff --git a/media/cast/transport/cast_transport_sender_impl.cc b/media/cast/transport/cast_transport_sender_impl.cc
index 8f07832d1c73851e4e9655397754a9fe82dbccab..06877b08ba5155c2f0d4794add8f4869959b1c32 100644
--- a/media/cast/transport/cast_transport_sender_impl.cc
+++ b/media/cast/transport/cast_transport_sender_impl.cc
@@ -56,6 +56,7 @@ CastTransportSenderImpl::CastTransportSenderImpl(
              transport_task_runner),
       rtcp_builder_(&pacer_),
       raw_events_callback_(raw_events_callback) {
+  DCHECK(clock_);
   if (!raw_events_callback_.is_null()) {
     DCHECK(raw_events_callback_interval > base::TimeDelta());
     event_subscriber_.reset(new SimpleEventSubscriber);
@@ -74,24 +75,42 @@ CastTransportSenderImpl::~CastTransportSenderImpl() {
 
 void CastTransportSenderImpl::InitializeAudio(
     const CastTransportAudioConfig& config) {
-  pacer_.RegisterAudioSsrc(config.rtp.config.ssrc);
-  audio_sender_.reset(new TransportAudioSender(
-      config, clock_, transport_task_runner_, &pacer_));
-  if (audio_sender_->initialized())
+  LOG_IF(WARNING, config.rtp.config.aes_key.empty() ||
+                  config.rtp.config.aes_iv_mask.empty())
+      << "Unsafe to send audio with encryption DISABLED.";
+  if (!audio_encryptor_.Initialize(config.rtp.config.aes_key,
+                                   config.rtp.config.aes_iv_mask)) {
+    status_callback_.Run(TRANSPORT_AUDIO_UNINITIALIZED);
+    return;
+  }
+  audio_sender_.reset(new RtpSender(clock_, transport_task_runner_, &pacer_));
+  if (audio_sender_->InitializeAudio(config)) {
+    pacer_.RegisterAudioSsrc(config.rtp.config.ssrc);
     status_callback_.Run(TRANSPORT_AUDIO_INITIALIZED);
-  else
+  } else {
+    audio_sender_.reset();
     status_callback_.Run(TRANSPORT_AUDIO_UNINITIALIZED);
+  }
 }
 
 void CastTransportSenderImpl::InitializeVideo(
     const CastTransportVideoConfig& config) {
-  pacer_.RegisterVideoSsrc(config.rtp.config.ssrc);
-  video_sender_.reset(new TransportVideoSender(
-      config, clock_, transport_task_runner_, &pacer_));
-  if (video_sender_->initialized())
+  LOG_IF(WARNING, config.rtp.config.aes_key.empty() ||
+                  config.rtp.config.aes_iv_mask.empty())
+      << "Unsafe to send video with encryption DISABLED.";
+  if (!video_encryptor_.Initialize(config.rtp.config.aes_key,
+                                   config.rtp.config.aes_iv_mask)) {
+    status_callback_.Run(TRANSPORT_VIDEO_UNINITIALIZED);
+    return;
+  }
+  video_sender_.reset(new RtpSender(clock_, transport_task_runner_, &pacer_));
+  if (video_sender_->InitializeVideo(config)) {
+    pacer_.RegisterVideoSsrc(config.rtp.config.ssrc);
     status_callback_.Run(TRANSPORT_VIDEO_INITIALIZED);
-  else
+  } else {
+    video_sender_.reset();
     status_callback_.Run(TRANSPORT_VIDEO_UNINITIALIZED);
+  }
 }
 
 void CastTransportSenderImpl::SetPacketReceiver(
@@ -99,16 +118,35 @@ void CastTransportSenderImpl::SetPacketReceiver(
   transport_->StartReceiving(packet_receiver);
 }
 
+namespace {
+void EncryptAndSendFrame(const EncodedFrame& frame,
+                         TransportEncryptionHandler* encryptor,
+                         RtpSender* sender) {
+  if (encryptor->initialized()) {
+    EncodedFrame encrypted_frame;
+    frame.CopyMetadataTo(&encrypted_frame);
+    if (encryptor->Encrypt(frame.frame_id, frame.data, &encrypted_frame.data)) {
+      sender->SendFrame(encrypted_frame);
+    } else {
+      LOG(ERROR) << "Encryption failed.  Not sending frame with ID "
+                 << frame.frame_id;
+    }
+  } else {
+    sender->SendFrame(frame);
+  }
+}
+}  // namespace
+
 void CastTransportSenderImpl::InsertCodedAudioFrame(
     const EncodedFrame& audio_frame) {
   DCHECK(audio_sender_) << "Audio sender uninitialized";
-  audio_sender_->SendFrame(audio_frame);
+  EncryptAndSendFrame(audio_frame, &audio_encryptor_, audio_sender_.get());
 }
 
 void CastTransportSenderImpl::InsertCodedVideoFrame(
     const EncodedFrame& video_frame) {
   DCHECK(video_sender_) << "Video sender uninitialized";
-  video_sender_->SendFrame(video_frame);
+  EncryptAndSendFrame(video_frame, &video_encryptor_, video_sender_.get());
 }
 
 void CastTransportSenderImpl::SendRtcpFromRtpSender(