Give DisconnectWindow some TLC.

remoting/host/disconnect_window.h

Index: remoting/host/disconnect_window.h
diff --git a/remoting/host/disconnect_window.h b/remoting/host/disconnect_window.h
index 51269b77fb47fea5c6bf2057d692a548a89df614..1bc053bba099046c19e6cb7944f93fd4cb59a945 100644
--- a/remoting/host/disconnect_window.h
+++ b/remoting/host/disconnect_window.h
@@ -20,20 +20,17 @@ class DisconnectWindow {
     kMaximumConnectedNameWidthInPixels = 400
   };
 
-  // DisconnectCallback is called when the user clicks on the Disconnect button
-  // to disconnect the session. This callback is provided as a parameter to the
-  // Show() method, and will be triggered on the UI thread.
-  typedef base::Callback<void(void)> DisconnectCallback;
-
   virtual ~DisconnectWindow() {}
 
-  // Shows the disconnect window allowing the user to disconnect the session.
-  // Returns false if the window could not be shown for any reason. The
-  // disconnect callback will be invoked if the user clicks the disconnect
-  // button, or if the window is closed for any reason other than Hide() being
-  // called
+  // Shows the disconnect window, allowing the user to disconnect the session.
+  // The window will display text from |ui_strings| and |username|.
+  // |disconnect_callback| will be invoked on the calling UI thread when the
+  // user chooses to disconnect, or if the window is closed by any means other
+  // than Hide(), or deletion of the DisconnectWindow instance.
+  // Show returns false if the window cannot be shown, in which case the
+  // callback will not be invoked.
   virtual bool Show(const UiStrings& ui_strings,
-                    const DisconnectCallback& disconnect_callback,
+                    const base::Closure& disconnect_callback,
                     const std::string& username) = 0;
 
   // Hides the disconnect window. The disconnect callback will not be invoked.