De-duplicate common code from StringPiece, StringPiece16, and their tests.

base/utf_offset_string_conversions.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 BASE_UTF_OFFSET_STRING_CONVERSIONS_H_
 #define BASE_UTF_OFFSET_STRING_CONVERSIONS_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/string16.h"
-
-namespace base {
-class StringPiece;
-class StringPiece16;
-}
+#include "base/string_piece.h"
 
 // Like the conversions in utf_string_conversions.h, but also takes one or more
 // offsets (|offset[s]_for_adjustment|) into the source strings, each offset
 // will be adjusted to point at the same logical place in the result strings.
 // If this isn't possible because an offset points past the end of the source
 // strings or into the middle of a multibyte sequence, the offending offset will
 // be set to string16::npos. |offset[s]_for_adjustment| may be NULL.
 BASE_EXPORT bool UTF8ToUTF16AndAdjustOffset(const char* src,
                                             size_t src_len,
                                             string16* output,
@@ skipping 56 matching lines @@
   void Add(const Adjustment& adjustment);
 
  private:
   void AdjustOffset(std::vector<size_t>::iterator offset);
 
   std::vector<size_t>* offsets_for_adjustment_;
   std::vector<Adjustment> adjustments_;
 };
 
 #endif  // BASE_UTF_OFFSET_STRING_CONVERSIONS_H_