Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

Review-Url: https://codereview.chromium.org/2793913007
Cr-Commit-Position: refs/heads/master@{#461858}
bool AXObject::isMenuRelated() const {
  switch (roleValue()) {
    case MenuRole:
    case MenuBarRole:
    case MenuButtonRole:
    case MenuItemRole:
    case MenuItemCheckBoxRole:
    case MenuItemRadioRole:
      return true;
    default:
      return false;
  }
}

bool AXObject::isMenuRelated() const {
  switch (roleValue()) {
    case MenuRole:
    case MenuBarRole:
    case MenuButtonRole:
    case MenuItemRole:
    case MenuItemCheckBoxRole:
    case MenuItemRadioRole:
      return true;
    default:
      return false;
  }
}
