Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

Review-Url: https://codereview.chromium.org/2793913007
Cr-Commit-Position: refs/heads/master@{#461858}
void AXObject::tokenVectorFromAttribute(Vector<String>& tokens,
                                        const QualifiedName& attribute) const {
  Node* node = this->getNode();
  if (!node || !node->isElementNode())
    return;

  String attributeValue = getAttribute(attribute).getString();
  if (attributeValue.isEmpty())
    return;

  attributeValue.simplifyWhiteSpace();
  attributeValue.split(' ', tokens);
}

void AXObject::tokenVectorFromAttribute(Vector<String>& tokens,
                                        const QualifiedName& attribute) const {
  Node* node = this->getNode();
  if (!node || !node->isElementNode())
    return;

  String attributeValue = getAttribute(attribute).getString();
  if (attributeValue.isEmpty())
    return;

  attributeValue.simplifyWhiteSpace();
  attributeValue.split(' ', tokens);
}
