Stop clamping tabIndex to short range

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

Index: third_party/WebKit/Source/core/dom/ElementRareData.h
diff --git a/third_party/WebKit/Source/core/dom/ElementRareData.h b/third_party/WebKit/Source/core/dom/ElementRareData.h
index 223da50f8dbd5322e8d99d8ddb9616e5c69d3295..7a35578e6121c78406e125eeb5f00516cb459914 100644
--- a/third_party/WebKit/Source/core/dom/ElementRareData.h
+++ b/third_party/WebKit/Source/core/dom/ElementRareData.h
@@ -60,15 +60,11 @@ class ElementRareData : public NodeRareData {
   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) {
     setElementFlag(TabIndexWasSetExplicitly, true);

[foolip, 2016/11/03 14:17:42]

Is this flag actually needed? Can't hasAttribute(tabindexAttr) be used instead?

[rwlbuis, 2016/11/03 15:33:09]

I still think we need the flag. If we do setAttribute("tabIndex",
crazy_big_number), the attribute will be set.
If we change Element::supportsFocus to test for hasAttribute instead of the
flag, in this
case the element with out-of-range tabIndex would still be focusable, which I
think we do not want to allow.

[foolip, 2016/11/03 16:06:57]

<button tabindex=18446744073709552001> seems to already be focusable, or am I
testing it wrong? What do other implementations do?

   }
 
   void clearTabIndexExplicitly() {
-    m_tabindex = 0;
     clearElementFlag(TabIndexWasSetExplicitly);
   }
 
@@ -192,8 +188,6 @@ class ElementRareData : public NodeRareData {
   CompositorProxiedPropertySet& ensureCompositorProxiedPropertySet();
   void clearCompositorProxiedPropertySet() { m_proxiedProperties = nullptr; }
 
-  short m_tabindex;
-
   LayoutSize m_minimumSizeForResizing;
   ScrollOffset m_savedLayerScrollOffset;
 
@@ -226,7 +220,6 @@ inline LayoutSize defaultMinimumSizeForResizing() {
 
 inline ElementRareData::ElementRareData(LayoutObject* layoutObject)
     : NodeRareData(layoutObject),
-      m_tabindex(0),
       m_minimumSizeForResizing(defaultMinimumSizeForResizing()),
       m_classList(nullptr) {
   m_isElementRareData = true;