remoting_me2me_host: Don't try to display UI on top of Mac login screen

remoting/host/remoting_me2me_host.cc

 // Copyright (c) 2012 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.
 //
 // This file implements a standalone host process for Me2Me.
 
 #include <string>
 
 #include "base/at_exit.h"
 #include "base/bind.h"
@@ skipping 231 matching lines @@
   virtual bool OnMessageReceived(const IPC::Message& message) {
     return false;
   }
 
   int Run() {
     if (!LoadConfig()) {
       return kInvalidHostConfigurationExitCode;
     }
 
 #if defined(OS_MACOSX) || defined(OS_WIN)
-    host_user_interface_.reset(new HostUserInterface(context_.get()));
-#endif
+    bool want_user_interface = true;
+
+#if defined(OS_MACOSX)
+    // Don't try to display any UI on top of the system's login screen as this
+    // is rejected by the Window Server on OS X 10.7.4, and prevents the
+    // capturer from working (http://crbug.com/140984).
+    base::mac::ScopedCFTypeRef<CFDictionaryRef> session(
+        CGSessionCopyCurrentDictionary());
+    const void* logged_in = CFDictionaryGetValue(session,
+                                                 kCGSessionLoginDoneKey);
+    if (logged_in != kCFBooleanTrue) {
+      want_user_interface = false;
+    }
+#endif  // OS_MACOSX
+
+    if (want_user_interface) {
+      host_user_interface_.reset(new HostUserInterface(context_.get()));
+    }
+#endif  // OS_MACOSX || OS_WIN
 
     StartWatchingPolicy();
 
 #if defined(OS_MACOSX) || defined(OS_WIN)
     context_->file_task_runner()->PostTask(
         FROM_HERE,
         base::Bind(&HostProcess::ListenForConfigChanges,
                    base::Unretained(this)));
 #endif
     message_loop_.Run();
@@ skipping 249 matching lines @@
 #endif
 
     heartbeat_sender_.reset(new HeartbeatSender(
         this, host_id_, signal_strategy_.get(), &key_pair_));
 
     log_to_server_.reset(
         new LogToServer(host_, ServerLogEntry::ME2ME, signal_strategy_.get()));
     host_event_logger_ = HostEventLogger::Create(host_, kApplicationName);
 
 #if defined(OS_MACOSX) || defined(OS_WIN)
-    host_user_interface_->Start(
-        host_, base::Bind(&HostProcess::OnDisconnectRequested,
-                          base::Unretained(this)));
+    if (host_user_interface_.get()) {
+      host_user_interface_->Start(
+          host_, base::Bind(&HostProcess::OnDisconnectRequested,
+                            base::Unretained(this)));
+    }
 #endif
 
     host_->Start();
 
     CreateAuthenticatorFactory();
   }
 
   void OnAuthFailed() {
     Shutdown(kInvalidOauthCredentialsExitCode);
   }
@@ skipping 195 matching lines @@
             user32.GetFunctionPointer("SetProcessDPIAware"));
     set_process_dpi_aware();
   }
 
   // CommandLine::Init() ignores the passed |argc| and |argv| on Windows getting
   // the command line from GetCommandLineW(), so we can safely pass NULL here.
   return main(0, NULL);
 }
 
 #endif  // defined(OS_WIN)