debugger: start moving to the async shutdown infrastructure

src/plugins/debugger/debuggerplugin.cpp

@@ -2551,9 +2551,18 @@ ExtensionSystem::IPlugin::ShutdownFlag DebuggerPlugin::aboutToShutdown()
         d->m_uiSwitcher->aboutToShutdown();
     //if (d->m_engine)
     //    d->m_engine->shutdown();
-    return SynchronousShutdown;
+
+    // FIXME: Notify all engines instead.
+    QTimer::singleShot(0, this, SLOT(emitShutdownFinished()));
+    return AsynchronousShutdown;
 }
 
+void DebuggerPlugin::emitShutdownFinished()
+{
+    emit asynchronousShutdownFinished();
+}
+
+
 void DebuggerPlugin::showMessage(const QString &msg, int channel, int timeout)
 {
     //qDebug() << "PLUGIN OUTPUT: " << channel << msg;

src/plugins/debugger/debuggerplugin.h

@@ -35,7 +35,6 @@
 #include <extensionsystem/iplugin.h>
 
 QT_BEGIN_NAMESPACE
-class QAbstractItemView;
 class QIcon;
 class QMessageBox;
 QT_END_NAMESPACE
@@ -119,8 +118,9 @@ signals:
 
 private:
     friend class Internal::DebuggerEngine;
-    friend class Internal::DebuggerListener
-;
+    friend class Internal::DebuggerListener;
+
+    Q_SLOT void emitShutdownFinished();
     bool initialize(const QStringList &arguments, QString *errorMessage);
     ShutdownFlag aboutToShutdown();
     void extensionsInitialized();