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

base/bits.h

 // Copyright (c) 2009 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.
 
 // This file defines some bit utilities.
 
 #ifndef BASE_BITS_H_
 #define BASE_BITS_H_
-#pragma once
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 
 namespace base {
 namespace bits {
 
 // Returns the integer i such as 2^i <= n < 2^(i+1)
 inline int Log2Floor(uint32 n) {
   if (n == 0)
@@ skipping 19 matching lines @@
   } else {
     // Log2Floor returns -1 for 0, so the following works correctly for n=1.
     return 1 + Log2Floor(n - 1);
   }
 }
 
 }  // namespace bits
 }  // namespace base
 
 #endif  // BASE_BITS_H_