Revert of Remove webrtc/libjingle/{xmllite,xmpp}

webrtc/libjingle/xmpp/saslmechanism.h

Index: webrtc/libjingle/xmpp/saslmechanism.h
diff --git a/webrtc/libjingle/xmpp/saslmechanism.h b/webrtc/libjingle/xmpp/saslmechanism.h
new file mode 100644
index 0000000000000000000000000000000000000000..9c392e56678ffce4f9e836af1db530d18b89a424
--- /dev/null
+++ b/webrtc/libjingle/xmpp/saslmechanism.h
@@ -0,0 +1,57 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_LIBJINGLE_XMPP_SASLMECHANISM_H_
+#define WEBRTC_LIBJINGLE_XMPP_SASLMECHANISM_H_
+
+#include <string>
+
+namespace buzz {
+
+class XmlElement;
+
+
+// Defines a mechnanism to do SASL authentication.
+// Subclass instances should have a self-contained way to present
+// credentials.
+class SaslMechanism {
+
+public:
+  
+  // Intended to be subclassed
+  virtual ~SaslMechanism() {}
+
+  // Should return the name of the SASL mechanism, e.g., "PLAIN"
+  virtual std::string GetMechanismName() = 0;
+
+  // Should generate the initial "auth" request.  Default is just <auth/>.
+  virtual XmlElement * StartSaslAuth();
+
+  // Should respond to a SASL "<challenge>" request.  Default is
+  // to abort (for mechanisms that do not do challenge-response)
+  virtual XmlElement * HandleSaslChallenge(const XmlElement * challenge);
+
+  // Notification of a SASL "<success>".  Sometimes information
+  // is passed on success.
+  virtual void HandleSaslSuccess(const XmlElement * success);
+
+  // Notification of a SASL "<failure>".  Sometimes information
+  // for the user is passed on failure.
+  virtual void HandleSaslFailure(const XmlElement * failure);
+
+protected:
+  static std::string Base64Encode(const std::string & plain);
+  static std::string Base64Decode(const std::string & encoded);
+  static std::string Base64EncodeFromArray(const char * plain, size_t length);
+};
+
+}
+
+#endif  // WEBRTC_LIBJINGLE_XMPP_SASLMECHANISM_H_