Add xmllite and xmpp sources to third_party/

third_party/libjingle_xmpp/xmllite/xmlconstants.cc

+// Copyright 2004 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/libjingle_xmpp/xmllite/xmlconstants.h"
+
+namespace buzz {
+
+const char STR_EMPTY[] = "";
+const char NS_XML[] = "http://www.w3.org/XML/1998/namespace";
+const char NS_XMLNS[] = "http://www.w3.org/2000/xmlns/";
+const char STR_XMLNS[] = "xmlns";
+const char STR_XML[] = "xml";
+const char STR_VERSION[] = "version";
+const char STR_ENCODING[] = "encoding";
+
+const StaticQName QN_XMLNS = { STR_EMPTY, STR_XMLNS };
+
+}  // namespace buzz