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

base/utf_string_conversion_utils.h

 // Copyright (c) 2011 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_UTF_STRING_CONVERSION_UTILS_H_
 #define BASE_UTF_STRING_CONVERSION_UTILS_H_
-#pragma once
 
 // This should only be used by the various UTF string conversion files.
 
 #include "base/base_export.h"
 #include "base/string16.h"
 
 namespace base {
 
 inline bool IsValidCodepoint(uint32 code_point) {
   // Excludes the surrogate code points ([0xD800, 0xDFFF]) and
@@ skipping 71 matching lines @@
 void PrepareForUTF8Output(const CHAR* src, size_t src_len, std::string* output);
 
 // Prepares an output buffer (containing either UTF-16 or -32 data) given some
 // UTF-8 input that will be converted to it.  See PrepareForUTF8Output().
 template<typename STRING>
 void PrepareForUTF16Or32Output(const char* src, size_t src_len, STRING* output);
 
 }  // namespace base
 
 #endif  // BASE_UTF_STRING_CONVERSION_UTILS_H_