system_wrappers: Fix include header guards.

webrtc/system_wrappers/include/event_tracer.h

 /*
  *  Copyright (c) 2012 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.
  */
 
 // This file defines the interface for event tracing in WebRTC.
 //
 // Event log handlers are set through SetupEventTracer(). User of this API will
 // provide two function pointers to handle event tracing calls.
 //
 // * GetCategoryEnabledPtr
 //   Event tracing system calls this function to determine if a particular
 //   event category is enabled.
 //
 // * AddTraceEventPtr
 //   Adds a tracing event. It is the user's responsibility to log the data
 //   provided.
 //
 // Parameters for the above two functions are described in trace_event.h.
 
-#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_EVENT_TRACER_H_
-#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_EVENT_TRACER_H_
+#ifndef WEBRTC_SYSTEM_WRAPPERS_INCLUDE_EVENT_TRACER_H_
+#define WEBRTC_SYSTEM_WRAPPERS_INCLUDE_EVENT_TRACER_H_
 
 // This file has moved.
 // TODO(tommi): Delete after removing dependencies and updating Chromium.
 #include "webrtc/base/event_tracer.h"
 
-#endif  // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_EVENT_TRACER_H_
+#endif  // WEBRTC_SYSTEM_WRAPPERS_INCLUDE_EVENT_TRACER_H_