Remove obsolete WebString comment from string_util

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 266 matching lines @@
 // (e.g. U+FFFE). It's done on purpose because all the existing callers want
 // to have the maximum 'discriminating' power from other encodings. If
 // there's a use case for just checking the structural validity, we have to
 // add a new function for that.
 //
 // IsStringASCII assumes the input is likely all ASCII, and does not leave early
 // if it is not the case.
 BASE_EXPORT bool IsStringUTF8(const StringPiece& str);
 BASE_EXPORT bool IsStringASCII(const StringPiece& str);
 BASE_EXPORT bool IsStringASCII(const StringPiece16& str);
-// A convenience adaptor for WebStrings, as they don't convert into
-// StringPieces directly.
 BASE_EXPORT bool IsStringASCII(const string16& str);
 #if defined(WCHAR_T_IS_UTF32)
 BASE_EXPORT bool IsStringASCII(const std::wstring& str);
 #endif
 
 // Compare the lower-case form of the given string against the given
 // previously-lower-cased ASCII string (typically a constant).
 BASE_EXPORT bool LowerCaseEqualsASCII(StringPiece str,
                                       StringPiece lowecase_ascii);
 BASE_EXPORT bool LowerCaseEqualsASCII(StringPiece16 str,
@@ skipping 161 matching lines @@
 
 #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
 
 #endif  // BASE_STRINGS_STRING_UTIL_H_