[Autofill] Fix of crashes caused by show-autofill-signatures flag

components/autofill/core/common/autofill_util.h

 // Copyright 2015 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_AUTOFILL_CORE_COMMON_AUTOFILL_UTIL_H_
 #define COMPONENTS_AUTOFILL_CORE_COMMON_AUTOFILL_UTIL_H_
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
 
 #include "base/strings/string16.h"
 #include "components/autofill/core/common/form_field_data.h"
 
 namespace autofill {
 
 // Returns true when command line switch |kEnableSuggestionsWithSubstringMatch|
 // is on.
 bool IsFeatureSubstringMatchEnabled();
 
+// Returns true if showing autofill signature as HTML attributes is enabled.
+bool IsShowAutofillSignaturesEnabled();
+
 // Returns true when keyboard accessory is enabled.
 bool IsKeyboardAccessoryEnabled();
 
 // A token is a sequences of contiguous characters separated by any of the
 // characters that are part of delimiter set {' ', '.', ',', '-', '_', '@'}.
 
 // Returns true if the |field_contents| is a substring of the |suggestion|
 // starting at token boundaries. |field_contents| can span multiple |suggestion|
 // tokens.
 bool FieldIsSuggestionSubstringStartingOnTokenBoundary(
@@ skipping 24 matching lines @@
 
 // Lowercases and tokenizes a given |attribute| string.
 // Considers any ASCII whitespace character as a possible separator.
 // Also ignores empty tokens, resulting in a collapsing of whitespace.
 std::vector<std::string> LowercaseAndTokenizeAttributeString(
     const std::string& attribute);
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_COMMON_AUTOFILL_UTIL_H_