Reuse the requestExpansion() signal from the base class

In addition correct the signatures of signals in BaseTreeModel.

Change-Id: I8c49105c9fcc1a6115c5e5c0dc8d9e87ff98d707
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/treemodel.h

@@ -207,8 +207,8 @@ protected:
     void destroyItem(TreeItem *item); // item is destroyed.
 
 signals:
-    void requestExpansion(QModelIndex);
-    void requestCollapse(QModelIndex);
+    void requestExpansion(const QModelIndex &);
+    void requestCollapse(const QModelIndex &);
 
 protected:
     friend class TreeItem;

src/plugins/autotest/testresultspane.cpp

@@ -152,7 +152,7 @@ TestResultsPane::TestResultsPane(QObject *parent) :
     connect(m_treeView, &ResultsTreeView::copyShortcutTriggered, [this] () {
         onCopyItemTriggered(getTestResult(m_treeView->currentIndex()));
     });
-    connect(m_model, &TestResultModel::requestExpansion, [this] (QModelIndex idx) {
+    connect(m_model, &TestResultModel::requestExpansion, [this] (const QModelIndex &idx) {
         m_treeView->expand(m_filterModel->mapFromSource(idx));
     });
     connect(TestRunner::instance(), &TestRunner::testRunStarted,

src/plugins/projectexplorer/projectmodels.h

@@ -92,7 +92,6 @@ public:
 
 signals:
     void renamed(const Utils::FilePath &oldName, const Utils::FilePath &newName);
-    void requestExpansion(const QModelIndex &index);
 
 private:
     bool m_filterProjects = false;