Switch to equalIgnoringASCIICase throughout modules/accessibility

BUG=627682

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

void AXObjectCacheImpl::childrenChanged(LayoutObject* layoutObject) {
  childrenChanged(get(layoutObject));
}
