Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

Review-Url: https://codereview.chromium.org/2793913007
Cr-Commit-Position: refs/heads/master@{#461858}
AccessibilityRole AXListBoxOption::determineAccessibilityRole() {
  if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
    return m_ariaRole;

  if (isParentPresentationalRole())
    return StaticTextRole;

  return ListBoxOptionRole;
}

AccessibilityRole AXListBoxOption::determineAccessibilityRole() {
  if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
    return m_ariaRole;

  if (isParentPresentationalRole())
    return StaticTextRole;

  return ListBoxOptionRole;
}
