CppTools: Remove processEvents call from follow symbol

processEvents is a bad way of dealing with asynchronous
requests. Use QFutureWatcher for that purpose.

Change-Id: I3839cb9db80a6d391f6af1178e96986a325b7b99
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/libs/utils/link.h

@@ -28,6 +28,8 @@
 #include <QString>
 #include <qmetatype.h>
 
+#include <functional>
+
 namespace Utils {
 
 struct Link
@@ -57,6 +59,8 @@ struct Link
     int targetColumn;
 };
 
+using ProcessLinkCallback = std::function<void(const Link &)>;
+
 } // namespace Utils
 
 Q_DECLARE_METATYPE(Utils::Link)