Fix race condition disconnecting hosts.

remoting/host/it2me_host_user_interface.h

Index: remoting/host/it2me_host_user_interface.h
diff --git a/remoting/host/it2me_host_user_interface.h b/remoting/host/it2me_host_user_interface.h
index 11d39d69306f8b03f4a0e52283dd467a19e1464d..23e4750f1063a098e766f8b25f69ac912c8c3ca9 100644
--- a/remoting/host/it2me_host_user_interface.h
+++ b/remoting/host/it2me_host_user_interface.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/synchronization/waitable_event.h"
 
 #include "remoting/base/scoped_thread_proxy.h"
 #include "remoting/host/host_status_observer.h"
@@ -67,11 +68,8 @@ class It2MeHostUserInterface : public HostStatusObserver {
                 ContinueWindow* continue_window,
                 LocalInputMonitor* monitor);
 
-  void OnConnect(const std::string& username);
-  void OnLastDisconnect();
-
-  void ProcessOnConnect(const std::string& username);
-  void ProcessOnLastDisconnect();
+  void ProcessOnClientAuthenticated(const std::string& username);
+  void ProcessOnClientDisconnected();
 
   void MonitorLocalInputs(bool enable);
 
@@ -119,6 +117,10 @@ class It2MeHostUserInterface : public HostStatusObserver {
   // is connected).
   std::string authenticated_jid_;
 
+  // Event to allow the On* callbacks to block until their counterparts on the
+  // UI thread have completed.
+  base::WaitableEvent callback_complete_;
+
   DISALLOW_COPY_AND_ASSIGN(It2MeHostUserInterface);
 };