[WIP][DO NOT LAND] Componentize spellcheck

chrome/browser/spellchecker/word_trimmer.h

-// Copyright (c) 2011 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 CHROME_BROWSER_SPELLCHECKER_WORD_TRIMMER_H_
-#define CHROME_BROWSER_SPELLCHECKER_WORD_TRIMMER_H_
-
-#include <stddef.h>
-
-#include "base/strings/string16.h"
-
-// Trims |text| to contain only the range from |start| to |end| and |keep| words
-// on either side of the range. The |start| and |end| parameters are character
-// indexes into |text|. The |keep| parameter is the number of words to keep on
-// either side of the |start|-|end| range. The function updates |start| in
-// accordance with the trimming.
-//
-// Example:
-//
-//  size_t start = 14;
-//  size_t end = 23;
-//  base::string16 text =
-//      base::ASCIIToUTF16("one two three four five six seven eight");
-//  int keep = 2;
-//  base::string16 trimmed = TrimWords(&start, end, text, keep);
-//  DCHECK(trimmed == base::ASCIIToUTF16("two three four five six seven"));
-//  DCHECK(start == 10);
-//
-base::string16 TrimWords(size_t* start,
-                         size_t end,
-                         const base::string16& text,
-                         size_t keep);
-
-#endif  // CHROME_BROWSER_SPELLCHECKER_WORD_TRIMMER_H_