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

base/test/values_test_util.h

 // Copyright (c) 2012 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_TEST_VALUES_TEST_UTIL_H_
 #define BASE_TEST_VALUES_TEST_UTIL_H_
-#pragma once
 
 #include <string>
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 class StringValue;
 
 // All the functions below expect that the value for the given key in
 // the given dictionary equals the given expected value.
@@ skipping 18 matching lines @@
                            const DictionaryValue& value,
                            const std::string& key);
 
 // Takes ownership of |actual|.
 void ExpectStringValue(const std::string& expected_str,
                        StringValue* actual);
 
 }  // namespace base
 
 #endif  // BASE_TEST_VALUES_TEST_UTIL_H_