Move EmptyString, kWhitespace and the BOM to base.

base/strings/string_util_constants.cc

 // 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.
 
 #include "base/strings/string_util.h"
 
+namespace base {
+
 #define WHITESPACE_UNICODE \
   0x0009, /* <control-0009> to <control-000D> */ \
   0x000A,                                        \
   0x000B,                                        \
   0x000C,                                        \
   0x000D,                                        \
   0x0020, /* Space */                            \
   0x0085, /* <control-0085> */                   \
   0x00A0, /* No-Break Space */                   \
   0x1680, /* Ogham Space Mark */                 \
@@ skipping 29 matching lines @@
   0x09,    // <control-0009> to <control-000D>
   0x0A,
   0x0B,
   0x0C,
   0x0D,
   0x20,    // Space
   0
 };
 
 const char kUtf8ByteOrderMark[] = "\xEF\xBB\xBF";
+
+}  // namespace base