Move a bunch of windows stuff from ui/base/win to ui/gfx/win

ui/base/text/utf16_indexing.h

-// Copyright (c) 2012 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 UI_BASE_TEXT_UTF16_INDEXING_H_
-#define UI_BASE_TEXT_UTF16_INDEXING_H_
-
-#include "base/strings/string16.h"
-#include "ui/base/ui_export.h"
-
-namespace ui {
-
-// Returns false if s[index-1] is a high surrogate and s[index] is a low
-// surrogate, true otherwise.
-UI_EXPORT bool IsValidCodePointIndex(const string16& s, size_t index);
-
-// |UTF16IndexToOffset| returns the number of code points between |base| and
-// |pos| in the given string. |UTF16OffsetToIndex| returns the index that is
-// |offset| code points away from the given |base| index. These functions are
-// named after glib's |g_utf8_pointer_to_offset| and |g_utf8_offset_to_pointer|,
-// which perform the same function for UTF-8. As in glib, it is an error to
-// pass an |offset| that walks off the edge of the string.
-//
-// These functions attempt to deal with invalid use of UTF-16 surrogates in a
-// way that makes as much sense as possible: unpaired surrogates are treated as
-// single characters, and if an argument index points to the middle of a valid
-// surrogate pair, it is treated as though it pointed to the end of that pair.
-// The index returned by |UTF16OffsetToIndex| never points to the middle of a
-// surrogate pair.
-//
-// The following identities hold:
-//   If |s| contains no surrogate pairs, then
-//     UTF16IndexToOffset(s, base, pos) == pos - base
-//     UTF16OffsetToIndex(s, base, offset) == base + offset
-//   If |pos| does not point to the middle of a surrogate pair, then
-//     UTF16OffsetToIndex(s, base, UTF16IndexToOffset(s, base, pos)) == pos
-//   Always,
-//     UTF16IndexToOffset(s, base, UTF16OffsetToIndex(s, base, ofs)) == ofs
-//     UTF16IndexToOffset(s, i, j) == -UTF16IndexToOffset(s, j, i)
-UI_EXPORT ptrdiff_t UTF16IndexToOffset(const string16& s,
-                                       size_t base,
-                                       size_t pos);
-UI_EXPORT size_t UTF16OffsetToIndex(const string16& s,
-                                    size_t base,
-                                    ptrdiff_t offset);
-
-}  // namespace ui
-
-#endif  // UI_BASE_TEXT_UTF16_INDEXING_H_