Remove video_channel() from Session interface

remoting/protocol/connection_to_host.cc

Index: remoting/protocol/connection_to_host.cc
diff --git a/remoting/protocol/connection_to_host.cc b/remoting/protocol/connection_to_host.cc
index 580f1984fbc290e80bcffd8a345d3a41ac5b9e3d..bf335c2646737c155d7ea2f887db237cbf045e72 100644
--- a/remoting/protocol/connection_to_host.cc
+++ b/remoting/protocol/connection_to_host.cc
@@ -172,8 +172,7 @@ void ConnectionToHost::OnSessionStateChange(
   switch (state) {
     case Session::FAILED:
       state_ = STATE_FAILED;
-      CloseChannels();
-      event_callback_->OnConnectionFailed(this);
+      CloseOnError();
       break;
 
     case Session::CLOSED:
@@ -186,7 +185,10 @@ void ConnectionToHost::OnSessionStateChange(
       state_ = STATE_CONNECTED;
       // Initialize reader and writer.
       video_reader_.reset(VideoReader::Create(session_->config()));
-      video_reader_->Init(session_.get(), video_stub_);
+      video_reader_->Init(
+          session_.get(), video_stub_,
+          base::Bind(&ConnectionToHost::OnVideoChannelInitialized,
+                     base::Unretained(this)));
       host_control_sender_.reset(
           new HostControlSender(session_->control_channel()));
       dispatcher_->Initialize(session_.get(), client_stub_);
@@ -199,12 +201,27 @@ void ConnectionToHost::OnSessionStateChange(
   }
 }
 
+void ConnectionToHost::OnVideoChannelInitialized(bool successful) {
+  if (!successful) {
+    CloseOnError();
+    return;
+  }
+}
+
+void ConnectionToHost::CloseOnError() {
+  state_ = STATE_FAILED;
+  CloseChannels();
+  event_callback_->OnConnectionFailed(this);
+}
+
 void ConnectionToHost::CloseChannels() {
   if (input_sender_.get())
     input_sender_->Close();
 
   if (host_control_sender_.get())
     host_control_sender_->Close();
+
+  video_reader_.reset();
 }
 
 void ConnectionToHost::OnClientAuthenticated() {