Move EmptyString, kWhitespace and the BOM to base.

base/strings/string_util.h

 // 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.
 //
 // This file defines utility functions for working with strings.
 
 #ifndef BASE_STRINGS_STRING_UTIL_H_
 #define BASE_STRINGS_STRING_UTIL_H_
 
 #include <ctype.h>
@@ skipping 105 matching lines @@
   }
 };
 
 template<typename Char> struct CaseInsensitiveCompareASCII {
  public:
   bool operator()(Char x, Char y) const {
     return ToLowerASCII(x) == ToLowerASCII(y);
   }
 };
 
+// These threadsafe functions return references to globally unique empty
+// strings.
+//
+// It is likely faster to construct a new empty string object (just a few
+// instructions to set the length to 0) than to get the empty string singleton
+// returned by these functions (which requires threadsafe singleton access).
+//
+// Therefore, DO NOT USE THESE AS A GENERAL-PURPOSE SUBSTITUTE FOR DEFAULT
+// CONSTRUCTORS. There is only one case where you should use these: functions
+// which need to return a string by reference (e.g. as a class member
+// accessor), and don't have an empty string to use (e.g. in an error case).
+// These should not be used as initializers, function arguments, or return
+// values for functions which return by value or outparam.
+BASE_EXPORT const std::string& EmptyString();
+BASE_EXPORT const string16& EmptyString16();
+
+// Contains the set of characters representing whitespace in the corresponding
+// encoding. Null-terminated.
+BASE_EXPORT extern const wchar_t kWhitespaceWide[];
+BASE_EXPORT extern const char16 kWhitespaceUTF16[];
+BASE_EXPORT extern const char kWhitespaceASCII[];
+
+// Null-terminated string representing the UTF-8 byte order mark.
+BASE_EXPORT extern const char kUtf8ByteOrderMark[];
+
 }  // namespace base
 
 #if defined(OS_WIN)
 #include "base/strings/string_util_win.h"
 #elif defined(OS_POSIX)
 #include "base/strings/string_util_posix.h"
 #else
 #error Define string operations appropriately for your platform
 #endif
 
-// These threadsafe functions return references to globally unique empty
-// strings.
-//
-// DO NOT USE THESE AS A GENERAL-PURPOSE SUBSTITUTE FOR DEFAULT CONSTRUCTORS.
-// There is only one case where you should use these: functions which need to
-// return a string by reference (e.g. as a class member accessor), and don't
-// have an empty string to use (e.g. in an error case).  These should not be
-// used as initializers, function arguments, or return values for functions
-// which return by value or outparam.
-BASE_EXPORT const std::string& EmptyString();
-BASE_EXPORT const string16& EmptyString16();
-
-BASE_EXPORT extern const wchar_t kWhitespaceWide[];
-BASE_EXPORT extern const char16 kWhitespaceUTF16[];
-BASE_EXPORT extern const char kWhitespaceASCII[];
-
-BASE_EXPORT extern const char kUtf8ByteOrderMark[];
-
 // Removes characters in |remove_chars| from anywhere in |input|.  Returns true
 // if any characters were removed.  |remove_chars| must be null-terminated.
 // NOTE: Safe to use the same variable for both |input| and |output|.
 BASE_EXPORT bool RemoveChars(const string16& input,
                              const char16 remove_chars[],
                              string16* output);
 BASE_EXPORT bool RemoveChars(const std::string& input,
                              const char remove_chars[],
                              std::string* output);
 
@@ skipping 199 matching lines @@
     return c - '0';
   if (c >= 'A' && c <= 'F')
     return c - 'A' + 10;
   if (c >= 'a' && c <= 'f')
     return c - 'a' + 10;
   return 0;
 }
 
 // Returns true if it's a whitespace character.
 inline bool IsWhitespace(wchar_t c) {
-  return wcschr(kWhitespaceWide, c) != NULL;
+  return wcschr(base::kWhitespaceWide, c) != NULL;
 }
 
 // Return a byte string in human-readable format with a unit suffix. Not
 // appropriate for use in any UI; use of FormatBytes and friends in ui/base is
 // highly recommended instead. TODO(avi): Figure out how to get callers to use
 // FormatBytes instead; remove this.
 BASE_EXPORT string16 FormatBytesUnlocalized(int64 bytes);
 
 // Starting at |start_offset| (usually 0), replace the first instance of
 // |find_this| with |replace_with|.
@@ skipping 133 matching lines @@
 #elif defined(WCHAR_T_IS_UTF32)
   typedef uint32 Unsigned;
 #endif
 };
 template<>
 struct ToUnsigned<short> {
   typedef unsigned short Unsigned;
 };
 
 #endif  // BASE_STRINGS_STRING_UTIL_H_