Stop clamping tabIndex to short range

third_party/WebKit/Source/core/dom/ElementRareData.h

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 42 matching lines @@
  public:
   static ElementRareData* create(LayoutObject* layoutObject) {
     return new ElementRareData(layoutObject);
   }
 
   ~ElementRareData();
 
   void setPseudoElement(PseudoId, PseudoElement*);
   PseudoElement* pseudoElement(PseudoId) const;
 
-  short tabIndex() const { return m_tabindex; }
-
-  void setTabIndexExplicitly(short index) {
-    m_tabindex = index;
+  void setTabIndexExplicitly(int index) {

[kochi, 2016/11/04 06:49:35]

You can remove the parameter here.

[rwlbuis, 2016/11/04 13:03:18]

Done.

     setElementFlag(TabIndexWasSetExplicitly, true);
   }
 
   void clearTabIndexExplicitly() {
-    m_tabindex = 0;
     clearElementFlag(TabIndexWasSetExplicitly);
   }
 
   CSSStyleDeclaration& ensureInlineCSSStyleDeclaration(Element* ownerElement);
   InlineStylePropertyMap& ensureInlineStylePropertyMap(Element* ownerElement);
 
   InlineStylePropertyMap* inlineStylePropertyMap() {
     return m_cssomMapWrapper.get();
   }
 
@@ skipping 103 matching lines @@
   }
   ResizeObserverDataMap& ensureResizeObserverData();
 
   DECLARE_TRACE_AFTER_DISPATCH();
   DECLARE_TRACE_WRAPPERS_AFTER_DISPATCH();
 
  private:
   CompositorProxiedPropertySet& ensureCompositorProxiedPropertySet();
   void clearCompositorProxiedPropertySet() { m_proxiedProperties = nullptr; }
 
-  short m_tabindex;

[kochi, 2016/11/04 06:49:35]

Didn't you get any error for SameSizeAsElementRareData?

I think if you remove this member, you have to also remove
'short indices[1]' member in SameSizeAsElementRareData in
Element.cpp.

[kochi, 2016/11/04 07:17:04]

I figured out.
The last member of NodeRareData (which is the parent of
ElementRareData class) is a bitfield and take one byte.
As one short can fit in the padding to the next
"LayoutSize" (4-byte aligned).

So the ElementRareData size doesn't change with this anyway,
but you should still remove the 'short indices[1]' line in
SameSizeAsElementRareData in Element.cpp to avoid future
confusion.

[rwlbuis, 2016/11/04 13:03:18]

Thanks for looking into it, I forgot about this. I simply removed the entry in
the struct in my latest patch.

[rwlbuis, 2016/11/04 13:03:18]

Acknowledged.

-
   LayoutSize m_minimumSizeForResizing;
   ScrollOffset m_savedLayerScrollOffset;
 
   Member<DatasetDOMStringMap> m_dataset;
   Member<ElementShadow> m_shadow;
   Member<ClassList> m_classList;
   Member<NamedNodeMap> m_attributeMap;
   Member<AttrNodeList> m_attrNodeList;
   Member<InlineCSSStyleDeclaration> m_cssomWrapper;
   Member<InlineStylePropertyMap> m_cssomMapWrapper;
@@ skipping 12 matching lines @@
 
   explicit ElementRareData(LayoutObject*);
 };
 
 inline LayoutSize defaultMinimumSizeForResizing() {
   return LayoutSize(LayoutUnit::max(), LayoutUnit::max());
 }
 
 inline ElementRareData::ElementRareData(LayoutObject* layoutObject)
     : NodeRareData(layoutObject),
-      m_tabindex(0),
       m_minimumSizeForResizing(defaultMinimumSizeForResizing()),
       m_classList(nullptr) {
   m_isElementRareData = true;
 }
 
 inline ElementRareData::~ElementRareData() {
   DCHECK(!m_pseudoElementData);
 }
 
 inline bool ElementRareData::hasPseudoElements() const {
@@ skipping 35 matching lines @@
 inline CompositorProxiedPropertySet&
 ElementRareData::ensureCompositorProxiedPropertySet() {
   if (!m_proxiedProperties)
     m_proxiedProperties = CompositorProxiedPropertySet::create();
   return *m_proxiedProperties;
 }
 
 }  // namespace blink
 
 #endif  // ElementRareData_h