Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

Review-Url: https://codereview.chromium.org/2793913007
Cr-Commit-Position: refs/heads/master@{#461858}
void AXObjectCacheImpl::remove(LayoutObject* layoutObject) {
  if (!layoutObject)
    return;

  AXID axID = m_layoutObjectMapping.at(layoutObject);
  remove(axID);
  m_layoutObjectMapping.erase(layoutObject);
}

void AXObjectCacheImpl::remove(LayoutObject* layoutObject) {
  if (!layoutObject)
    return;

  AXID axID = m_layoutObjectMapping.at(layoutObject);
  remove(axID);
  m_layoutObjectMapping.erase(layoutObject);
}
