Hide variable chooser if current edit widget is hidden

Change-Id: I4b908fd76602170a186b9e1430c7d0e65046d17d
Task-number: QTCREATORBUG-13355
Reviewed-by: Robert Loehning <robert.loehning@theqtcompany.com>
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/coreplugin/variablechooser.cpp

@@ -567,6 +567,8 @@ bool VariableChooser::eventFilter(QObject *obj, QEvent *event)
         return handleEscapePressed(ke, this);
     } else if (event->type() == QEvent::Resize) {
         d->updateButtonGeometry();
+    } else if (event->type() == QEvent::Hide) {
+        close();
     }
     return false;
 }