Pull out IDN_Spoof_Checker to separate cc/h files.

components/url_formatter/idn_spoof_checker.h

+// Copyright 2017 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 COMPONENTS_URL_FORMATTER_IDN_SPOOF_CHECKER_H_
+#define COMPONENTS_URL_FORMATTER_IDN_SPOOF_CHECKER_H_
+
+#include <memory>
+#include <string>
+
+#include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
+#include "third_party/icu/source/common/unicode/uniset.h"
+#include "third_party/icu/source/common/unicode/utypes.h"
+#include "third_party/icu/source/common/unicode/uversion.h"
+
+// 'icu' does not work. Use U_ICU_NAMESPACE.
+namespace U_ICU_NAMESPACE {
+
+class UnicodeString;
+
+}  // namespace U_ICU_NAMESPACE
+
+struct USpoofChecker;
+
+namespace url_formatter {
+
+// A helper class for IDN Spoof checking, used to ensure that no IDN input is
+// spoofable per Chromium's standard of spoofability. For a more thorough
+// explanation of how spoof checking works in Chromium, see
+// http://dev.chromium.org/developers/design-documents/idn-in-google-chrome .
+
+class IDNSpoofChecker {
+ public:
+  IDNSpoofChecker();
+  ~IDNSpoofChecker();
+
+  // Returns true if |label| is safe to display as Unicode. In the event of
+  // library failure, all IDN inputs will be treated as unsafe.
+  // See the function body for details on the specific safety checks performed.
+  bool SafeToDisplayAsUnicode(base::StringPiece16 label, bool is_tld_ascii);
+
+ private:
+  // Sets allowed characters in IDN labels and turns on USPOOF_CHAR_LIMIT.
+  void SetAllowedUnicodeSet(UErrorCode* status);
+  // Returns true if all the Cyrillic letters in |label| belong to a set of
+  // Cyrillic letters that look like ASCII Latin letters.
+  bool IsMadeOfLatinAlikeCyrillic(const icu::UnicodeString& label);
+
+  USpoofChecker* checker_;
+  icu::UnicodeSet deviation_characters_;
+  icu::UnicodeSet non_ascii_latin_letters_;
+  icu::UnicodeSet kana_letters_exceptions_;
+  icu::UnicodeSet cyrillic_letters_;
+  icu::UnicodeSet cyrillic_letters_latin_alike_;
+
+  IDNSpoofChecker(const IDNSpoofChecker&) = delete;
+  void operator=(const IDNSpoofChecker&) = delete;
+};
+
+}  // namespace url_formatter
+
+#endif  // COMPONENTS_URL_FORMATTER_IDN_SPOOF_CHECKER_H_