Improve performance of HTMLSelectElement::setActiveSelectionAnchor().

third_party/WebKit/Source/core/html/HTMLSelectElement.h

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 182 matching lines @@
     void dispatchInputAndChangeEventForMenuList();
 
     void recalcListItems() const;
     enum ResetReason {
         ResetReasonSelectedOptionRemoved,
         ResetReasonOthers
     };
     void resetToDefaultSelection(ResetReason = ResetReasonOthers);
     void typeAheadFind(KeyboardEvent*);
     void saveLastSelection();
+    void saveListboxActiveSelection();
     // Returns the first selected OPTION, or nullptr.
     HTMLOptionElement* selectedOption() const;
 
     bool isOptionalFormControl() const override { return !isRequiredFormControl(); }
     bool isRequiredFormControl() const override;
 
     bool hasPlaceholderLabelOption() const;
 
     enum SelectOptionFlag {
         DeselectOtherOptions = 1 << 0,
@@ skipping 69 matching lines @@
 
     FRIEND_TEST_ALL_PREFIXES(HTMLSelectElementTest, FirstSelectableOption);
     FRIEND_TEST_ALL_PREFIXES(HTMLSelectElementTest, LastSelectableOption);
     FRIEND_TEST_ALL_PREFIXES(HTMLSelectElementTest, NextSelectableOption);
     FRIEND_TEST_ALL_PREFIXES(HTMLSelectElementTest, PreviousSelectableOption);
 };
 
 } // namespace blink
 
 #endif // HTMLSelectElement_h