Remove no-non-virtual-dtor flag

BZ: 111473

The warning non-virtual-dtor should not be ignored for the whole project, but
only in the few cases where it it necessary.

Change-Id: I0ede82a30f2cd055b789f7fb56104fb227934e6f
Signed-off-by: Sebastien Gonzalve <sebastien.gonzalve@intel.com>
Signed-off-by: Guilhem IMBERTON <guilhem.imberton@intel.com>
Reviewed-on: http://android.intel.com:8080/110191
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>
diff --git a/xmlserializer/XmlSource.h b/xmlserializer/XmlSource.h
index 818298d..1a7c52e 100644
--- a/xmlserializer/XmlSource.h
+++ b/xmlserializer/XmlSource.h
@@ -31,4 +31,7 @@
 {
 public:
     virtual void toXml(CXmlElement& xmlElement, CXmlSerializingContext& serializingContext) const = 0;
+
+protected:
+    virtual ~IXmlSource() {}
 };