base: Fix/add header #ifndef guards.

base/memory/memory_pressure_listener.h

 // Copyright 2013 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.
 
 // MemoryPressure provides static APIs for handling memory pressure on
 // platforms that have such signals, such as Android and ChromeOS.
 // The app will try to discard buffers that aren't deemed essential (individual
 // modules will implement their own policy).
 
-#ifndef BASE_MEMORY_PRESSURE_LISTENER_H_
-#define BASE_MEMORY_PRESSURE_LISTENER_H_
+#ifndef BASE_MEMORY_MEMORY_PRESSURE_LISTENER_H_
+#define BASE_MEMORY_MEMORY_PRESSURE_LISTENER_H_
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/callback.h"
 
 namespace base {
 
 // To start listening, create a new instance, passing a callback to a
 // function that takes a MemoryPressureLevel parameter. To stop listening,
 // simply delete the listener object. The implementation guarantees
@@ skipping 53 matching lines @@
  private:
   void Notify(MemoryPressureLevel memory_pressure_level);
 
   MemoryPressureCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryPressureListener);
 };
 
 }  // namespace base
 
-#endif  // BASE_MEMORY_PRESSURE_LISTENER_H_
+#endif  // BASE_MEMORY_MEMORY_PRESSURE_LISTENER_H_