Debugger: Replace virtuals by capability flags.

Change-Id: If09efd21dc44e356eb575bb6170356fdbd409b39
Reviewed-on: http://codereview.qt.nokia.com/2625
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/gdb/gdbengine.h

@@ -238,7 +238,6 @@ private: ////////// General Interface //////////
     virtual void runEngine();
 
     virtual unsigned debuggerCapabilities() const;
-    virtual bool canWatchWidgets() const;
     virtual void detachDebugger();
     virtual void shutdownEngine();
     virtual void shutdownInferior();