Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

Review-Url: https://codereview.chromium.org/2793913007
Cr-Commit-Position: refs/heads/master@{#461858}
bool AXNodeObject::isNonNativeTextControl() const {
  if (isNativeTextControl())
    return false;

  if (hasContentEditableAttributeSet())
    return true;

  if (isARIATextControl())
    return true;

  return false;
}

bool AXNodeObject::isNonNativeTextControl() const {
  if (isNativeTextControl())
    return false;

  if (hasContentEditableAttributeSet())
    return true;

  if (isARIATextControl())
    return true;

  return false;
}
