Switch usage of _DEBUG macro to NDEBUG.

webrtc/libjingle/xmpp/xmpptask.h

 /*
  *  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.
  */
 
@@ skipping 101 matching lines @@
                  public sigslot::has_slots<>
 {
  public:
   XmppTask(XmppTaskParentInterface* parent,
            XmppEngine::HandlerLevel level = XmppEngine::HL_NONE);
   virtual ~XmppTask();
 
   std::string task_id() const { return id_; }
   void set_task_id(std::string id) { id_ = id; }
 
-#ifdef _DEBUG
+#if !defined(NDEBUG)
   void set_debug_force_timeout(const bool f) { debug_force_timeout_ = f; }
 #endif
 
   virtual bool HandleStanza(const XmlElement* stanza) { return false; }
 
  protected:
   XmppReturnStatus SendStanza(const XmlElement* stanza);
   XmppReturnStatus SetResult(const std::string& code);
   XmppReturnStatus SendStanzaError(const XmlElement* element_original,
                                    XmppStanzaError code,
@@ skipping 22 matching lines @@
                            int per_x_seconds);
 
 private:
   void StopImpl();
 
   bool stopped_;
   std::deque<XmlElement*> stanza_queue_;
   rtc::scoped_ptr<XmlElement> next_stanza_;
   std::string id_;
 
-#ifdef _DEBUG
+#if !defined(NDEBUG)
   bool debug_force_timeout_;
 #endif
 };
 
 }  // namespace buzz
 
 #endif // WEBRTC_LIBJINGLE_XMPP_XMPPTASK_H_