QmlJS/C++: Fix possible crash on exit.

It could crash if a thread to find exported cpp types was still running
after the ModelManager was destroyed.

Change-Id: Ia48fac9c2ad1296992af83af57e84cce8c4f95ae
Reviewed-by: Leandro T. C. Melo <leandro.melo@nokia.com>

src/plugins/qmljstools/qmljsmodelmanager.h

@@ -69,6 +69,7 @@ class QMLJSTOOLS_EXPORT ModelManager: public QmlJS::ModelManagerInterface
 
 public:
     ModelManager(QObject *parent = 0);
+    ~ModelManager();
 
     void delayedInitialization();
 
@@ -129,8 +130,9 @@ private slots:
 
 private:
     static bool matchesMimeType(const Core::MimeType &fileMimeType, const Core::MimeType &knownMimeType);
-    static void updateCppQmlTypes(ModelManager *qmlModelManager,
-                                  CPlusPlus::CppModelManagerInterface *cppModelManager,
+    static void updateCppQmlTypes(QFutureInterface<void> &interface,
+                                  ModelManager *qmlModelManager,
+                                  CPlusPlus::Snapshot snapshot,
                                   QHash<QString, QPair<CPlusPlus::Document::Ptr, bool> > documents);
 
     mutable QMutex m_mutex;
@@ -144,6 +146,7 @@ private:
 
     QTimer *m_updateCppQmlTypesTimer;
     QHash<QString, QPair<CPlusPlus::Document::Ptr, bool> > m_queuedCppDocuments;
+    QFuture<void> m_cppQmlTypesUpdater;
 
     CppDataHash m_cppDataHash;
     mutable QMutex m_cppDataMutex;