Revert of Upstream string_util function.

ios/chrome/common/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.
-
-#ifndef IOS_CHROME_COMMON_STRING_UTIL_H_
-#define IOS_CHROME_COMMON_STRING_UTIL_H_
-
-#import <CoreGraphics/CoreGraphics.h>
-#import <Foundation/Foundation.h>
-#include <string>
-
-// Parses a string with an embedded link inside, delineated by BEGIN_LINK and
-// END_LINK. Returns the string without the link delimiters. If |out_link_range|
-// is not null, then it is filled out with the range of the link in the returned
-// string.
-// If no link is found, then it returns |text| and sets |out_link_range| to
-// {NSNotFound, 0}.
-NSString* ParseStringWithLink(NSString* text, NSRange* out_link_range);
-
-// Utility method that returns an NSCharacterSet containing Unicode graphics
-// and drawing characters (but not including the Braille Patterns characters).
-NSCharacterSet* GraphicCharactersSet();
-
-// Cleans an NSString by collapsing whitespace and (if |trim| is true)
-// removing leading and trailing spaces. If |removeGraphicChars| is true,
-// unicode graphic characters will also be removed from the string.
-NSString* CleanNSStringForDisplay(NSString* dirty,
-                                  BOOL removeGraphicChars,
-                                  BOOL trim);
-
-// Cleans a std::string identically to CleanNSStringForDisplay()
-std::string CleanStringForDisplay(std::string dirty,
-                                  BOOL removeGraphicChars,
-                                  BOOL trim);
-
-// Find the longest leading substring of |string| that, when rendered with
-// |attributes|, will fit on a single line inside |targetWidth|. If |trailing|
-// is YES, then find the trailing (instead of leading) substring.
-NSString* SubstringOfWidth(NSString* string,
-                           NSDictionary* attributes,
-                           CGFloat targetWidth,
-                           BOOL trailing);
-
-#endif  // IOS_CHROME_COMMON_STRING_UTIL_H_