CppEditor/CppTools: Avoid triggering garbage collector on editor close in tests

Closing an editor might trigger a timer which leads to the invocation of
the garbage collector. This is unfavourable for the plugin tests since a
test function closing an editor might influence a subsequent test
function (e.g. files get removed from the global snapshot although they
were added shortly before).

Change-Id: Ia80c11f99e2437fe145dc2d983b21962539b5181
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/cpptools/cpptoolstestcase.h

@@ -73,6 +73,8 @@ public:
     bool succeededSoFar() const;
     void closeEditorAtEndOfTestCase(Core::IEditor *editor);
 
+    static bool closeEditorWithoutGarbageCollectorInvocation(Core::IEditor *editor);
+
     static bool parseFiles(const QString &filePath);
     static bool parseFiles(const QStringList &filePaths);