scoped_ptr definitions for libxml2 objects

Change-Id: Iafbfce42d5cb91b0a5ddbf3149d434e10a4cb8d6

mpd/base/xml/scoped_xml_ptr.h

@@ -0,0 +1,28 @@
+// scoped_ptr alias for libxml2 objects. Deleters for the objects are also
+// defined in this file.
+#ifndef MPD_BASE_XML_SCOPED_XML_PTR_H_
+#define MPD_BASE_XML_SCOPED_XML_PTR_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "third_party/libxml/src/include/libxml/tree.h"
+
+namespace dash_packager {
+namespace xml {
+
+struct XmlDeleter {
+  // Called by scoped_ptr. http://goo.gl/YaLbcS
+  inline void operator()(xmlNodePtr ptr) const { xmlFreeNode(ptr); }
+  inline void operator()(xmlDocPtr ptr) const { xmlFreeDoc(ptr); }
+  inline void operator()(xmlChar* ptr) const { xmlFree(ptr); }
+};
+
+// C++11 allows template alias but standards before it do not. This struct is
+// for aliasing scoped_ptr with libxml2 object deleter.
+template <typename XmlType>
+struct ScopedXmlPtr {
+  typedef scoped_ptr<XmlType, XmlDeleter> type;
+};
+
+}  // namespace xml
+}  // namespace dash_packager
+#endif  // MPD_BASE_XML_SCOPED_XML_PTR_H_