HelloWorld: Do not use global object pool anymore

Change-Id: Ief4b53475fbe87f30b8305cf07dc14a5819e4662
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/helloworld/helloworldplugin.cpp

@@ -75,6 +75,7 @@ HelloWorldPlugin::HelloWorldPlugin()
 */
 HelloWorldPlugin::~HelloWorldPlugin()
 {
+    delete m_helloMode;
 }
 
 /*! Initializes the plugin. Returns true on success.
@@ -116,10 +117,8 @@ bool HelloWorldPlugin::initialize(const QStringList &arguments, QString *errorMe
             Core::ActionManager::actionContainer(Core::Constants::M_TOOLS);
     toolsMenu->addMenu(helloWorldMenu);
 
-    // Add a mode with a push button based on BaseMode. Like the BaseView,
-    // it will unregister itself from the plugin manager when it is deleted.
-    Core::IMode *helloMode = new HelloMode;
-    addAutoReleasedObject(helloMode);
+    // Add a mode with a push button based on BaseMode.
+    m_helloMode = new HelloMode;
 
     return true;
 }

src/plugins/helloworld/helloworldplugin.h

@@ -30,6 +30,8 @@
 namespace HelloWorld {
 namespace Internal {
 
+class HelloMode;
+
 class HelloWorldPlugin
   : public ExtensionSystem::IPlugin
 {
@@ -46,6 +48,8 @@ public:
 
 private:
     void sayHelloWorld();
+
+    HelloMode *m_helloMode = nullptr;
 };
 
 } // namespace Internal