Improve documentation for CefSettings.multi_threaded_message_loop

include/internal/cef_types.h

@@ -214,7 +214,8 @@ typedef struct _cef_settings_t {
   ///
   // Set to true (1) to have the browser process message loop run in a separate
   // thread. If false (0) than the CefDoMessageLoopWork() function must be
-  // called from your application message loop.
+  // called from your application message loop. This option is only supported on
+  // Windows.
   ///
   int multi_threaded_message_loop;