Code: AccessibilityExpanded AXNodeObject::isExpanded() const {
  if (getNode() && isHTMLSummaryElement(*getNode())) {
    if (getNode()->parentNode() &&
        isHTMLDetailsElement(getNode()->parentNode()))
      return toElement(getNode()->parentNode())->hasAttribute(openAttr)
                 ? ExpandedExpanded
                 : ExpandedCollapsed;
   }
 
   const AtomicString& expanded = getAttribute(aria_expandedAttr);
  if (equalIgnoringCase(expanded, "true"))
     return ExpandedExpanded;
  if (equalIgnoringCase(expanded, "false"))
     return ExpandedCollapsed;
 
   return ExpandedUndefined;
}

Vulnerability Type: Exec Code 
CWE ID: CWE-254
Summary: Google Chrome before 44.0.2403.89 does not ensure that the auto-open list omits all dangerous file types, which makes it easier for remote attackers to execute arbitrary code by providing a crafted file and leveraging a user's previous *Always open files of this type* choice, related to download_commands.cc and download_prefs.cc.
Commit Message: Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

Review-Url: https://codereview.chromium.org/2793913007
Cr-Commit-Position: refs/heads/master@{#461858}