Index: /trunk/include/VBox/HostServices/VBoxHostChannel.h
===================================================================
--- /trunk/include/VBox/HostServices/VBoxHostChannel.h	(revision 43785)
+++ /trunk/include/VBox/HostServices/VBoxHostChannel.h	(revision 43786)
@@ -169,4 +169,11 @@
     DECLR3CALLBACKMEMBER(void, HostChannelCallbackEvent, (void *pvCallbacks, void *pvChannel,
                                                           uint32_t u32Id, const void *pvEvent, uint32_t cbEvent));
+
+    /* The channel has been deleted by the provider. pvCallback will not be used anymore.
+     *
+     * @param pvCallbacks The callback context specified in HostChannelAttach.
+     * @param pvChannel   The channel instance returned by HostChannelAttach.
+     */
+    DECLR3CALLBACKMEMBER(void, HostChannelCallbackDeleted, (void *pvCallbacks, void *pvChannel));
 } VBOXHOSTCHANNELCALLBACKS;