Refactor IT2Me-specific functions into a HostObserver subclass.

remoting/host/chromoting_host.cc

Index: remoting/host/chromoting_host.cc
diff --git a/remoting/host/chromoting_host.cc b/remoting/host/chromoting_host.cc
index c6485779d4b0a86aad1e02217653900f07e8b837..4963d54fa95d355d24706ff1d00c78bf2e2def6d 100644
--- a/remoting/host/chromoting_host.cc
+++ b/remoting/host/chromoting_host.cc
@@ -203,9 +203,6 @@ void ChromotingHost::OnSessionAuthenticated(ClientSession* client) {
   // TODO(jamiewalch): Tidy up actions to be taken on connect/disconnect,
   // including closing the connection on failure of a critical operation.
   EnableCurtainMode(true);
-
-  std::string username = jid.substr(0, jid.find('/'));
-  desktop_environment_->OnConnect(username);
 }
 
 void ChromotingHost::OnSessionClosed(ClientSession* client) {
@@ -234,7 +231,6 @@ void ChromotingHost::OnSessionClosed(ClientSession* client) {
 
     // Disable the "curtain" if there are no more active clients.
     EnableCurtainMode(false);
-    desktop_environment_->OnLastDisconnect();
   }
 }
 
@@ -393,7 +389,6 @@ void ChromotingHost::PauseSession(bool pause) {
   for (client = clients_.begin(); client != clients_.end(); ++client) {
     (*client)->set_awaiting_continue_approval(pause);
   }
-  desktop_environment_->OnPause(pause);
 }
 
 void ChromotingHost::SetUiStrings(const UiStrings& ui_strings) {