Made CHostControl use atomic reference counting because it is accessed from S...

plugin/npapi_host_control/win/host_control.h

 // Copyright 2009, Google Inc.  All rights reserved.
 // Portions of this file were adapted from the Mozilla project.
 // See https://developer.mozilla.org/en/ActiveX_Control_for_Hosting_Netscape_Plug-ins_in_IE
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
@@ skipping 41 matching lines @@
 #include "base/scoped_ptr.h"
 
 // Directory not included, as this file is auto-generated from the
 // type library.
 #include "npapi_host_control.h"
 #include "plugin/npapi_host_control/win/np_browser_proxy.h"
 
 class NPPluginProxy;
 
 // Class implementing an ActiveX control for containing NPAPI plugin-objects.
+// This needs to be CComMultiThreadModel because these objects are concurrently
+// AddRefed and Released from StreamOperation threads.
 class ATL_NO_VTABLE CHostControl
-    : public CComObjectRootEx<CComSingleThreadModel>,
+    : public CComObjectRootEx<CComMultiThreadModel>,
       public CComCoClass<CHostControl, &CLSID_HostControl>,
       public CComControl<CHostControl>,
       // IMPORTANT IMPLEMENTATION NOTE:
       // Pass 0xFFFF to the major and minor versions of the IDispatchImpl
       // for trigger the behaviour in CComTypeInfoHolder::GetTI that forces
       // the type-library to be loaded from the module, not through the
       // registry.
       // Without this behaviour, the plug-in fails to load on Vista with UAC
       // disabled.  This is because all processes run at elevated integrity
       // with UAC disabled.  Because the plug-in is registered as a per-user
@@ skipping 185 matching lines @@
                         &LIBID_npapi_host_controlLib,
                         0xFFFF, 0xFFFF> DispatchImpl;
 
   DISALLOW_COPY_AND_ASSIGN(CHostControl);
 };
 
 // Register this COM class with the COM module.
 OBJECT_ENTRY_AUTO(__uuidof(HostControl), CHostControl);
 
 #endif  // O3D_PLUGIN_NPAPI_HOST_CONTROL_WIN_HOST_CONTROL_H_