Call the DisconnectWindow interface methods on the UI thread.

remoting/host/chromoting_host.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/chromoting_host.h"
 
 #include "build/build_config.h"
 #include "remoting/base/constants.h"
 #include "remoting/base/encoder.h"
 #include "remoting/base/encoder_row_based.h"
@@ skipping 354 matching lines @@
 
   // Close the connection to connection just to be safe.
   connection->Disconnect();
 
   // Also remove reference to ConnectionToClient from this object.
   clients_.erase(client);
 
   if (!HasAuthenticatedClients()) {
     EnableCurtainMode(false);
     if (is_me2mom_)
-      desktop_environment_->disconnect_window()->Hide();
+      ShowDisconnectWindow(false, std::string());
   }
 }
 
 // TODO(sergeyu): Move this to SessionManager?
 Encoder* ChromotingHost::CreateEncoder(const protocol::SessionConfig* config) {
   const protocol::ChannelConfig& video_config = config->video_config();
 
   if (video_config.codec == protocol::ChannelConfig::CODEC_VERBATIM) {
     return EncoderRowBased::CreateVerbatimEncoder();
   } else if (video_config.codec == protocol::ChannelConfig::CODEC_ZIP) {
@@ skipping 78 matching lines @@
 
   // Immediately add the connection and start the session.
   recorder_->AddConnection(connection);
   recorder_->Start();
   EnableCurtainMode(true);
   if (is_me2mom_) {
     std::string username = connection->session()->jid();
     size_t pos = username.find('/');
     if (pos != std::string::npos)
       username.replace(pos, std::string::npos, "");
-    desktop_environment_->disconnect_window()->Show(this, username);
+    ShowDisconnectWindow(true, username);
   }
 }
 
 void ChromotingHost::LocalLoginFailed(
     scoped_refptr<ConnectionToClient> connection) {
   if (MessageLoop::current() != context_->main_message_loop()) {
     context_->main_message_loop()->PostTask(
         FROM_HERE,
         NewRunnableMethod(this, &ChromotingHost::LocalLoginFailed, connection));
     return;
@@ skipping 11 matching lines @@
   // Find the client session corresponding to the given connection.
   ClientList::iterator client;
   for (client = clients_.begin(); client != clients_.end(); ++client) {
     if (client->get()->connection() == connection)
       break;
   }
   CHECK(client != clients_.end());
   client->get()->OnAuthorizationComplete(true);
 }
 
+void ChromotingHost::ShowDisconnectWindow(bool show,
+                                          const std::string& username) {
+  if (context_->ui_message_loop() != MessageLoop::current()) {
+    context_->ui_message_loop()->PostTask(
+        FROM_HERE,
+        NewRunnableMethod(this, &ChromotingHost::ShowDisconnectWindow,
+                          show, username));
+    return;
+  }
+
+  if (show) {
+    desktop_environment_->disconnect_window()->Show(this, username);
+  } else {
+    desktop_environment_->disconnect_window()->Hide();
+  }
+}
+
 }  // namespace remoting