Remove #pragma once. Just from base/ for now.

base/mac/scoped_aedesc.h

 // Copyright (c) 2010 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.
 
 #ifndef BASE_MAC_SCOPED_AEDESC_H_
 #define BASE_MAC_SCOPED_AEDESC_H_
-#pragma once
 
 #import <CoreServices/CoreServices.h>
 
 #include "base/basictypes.h"
 
 namespace base {
 namespace mac {
 
 // The ScopedAEDesc is used to scope AppleEvent descriptors.  On creation,
 // it will store a NULL descriptor.  On destruction, it will dispose of the
@@ skipping 26 matching lines @@
  private:
   AEDescType desc_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedAEDesc);
 };
 
 }  // namespace mac
 }  // namespace base
 
 #endif  // BASE_MAC_SCOPED_AEDESC_H_