If JavaScript shows a dialog, cause the page to lose fullscreen.

BUG=670135, 550017, 726761, 728276

Review-Url: https://codereview.chromium.org/2906133004
Cr-Commit-Position: refs/heads/master@{#478884}
void WebContentsImpl::UpdateUrlForUkmSource(ukm::UkmRecorder* service,
                                            ukm::SourceId ukm_source_id) {
  service->UpdateSourceURL(ukm_source_id, GetLastCommittedURL());
}

void WebContentsImpl::UpdateUrlForUkmSource(ukm::UkmRecorder* service,
                                            ukm::SourceId ukm_source_id) {
  service->UpdateSourceURL(ukm_source_id, GetLastCommittedURL());
}
