M57: Add UseCounter for ServiceWorkerNavigationPreload.

content/child/web_url_loader_impl.cc

Index: content/child/web_url_loader_impl.cc
diff --git a/content/child/web_url_loader_impl.cc b/content/child/web_url_loader_impl.cc
index 06ac3eb1a96939133b87e84768a533cea852cabc..b4aa478c989903af5535c4ab0f74b8b7d6774635 100644
--- a/content/child/web_url_loader_impl.cc
+++ b/content/child/web_url_loader_impl.cc
@@ -1087,6 +1087,8 @@ void WebURLLoaderImpl::PopulateURLResponse(const GURL& url,
       info.cors_exposed_header_names.end(), cors_exposed_header_names.begin(),
       [](const std::string& h) { return blink::WebString::fromLatin1(h); });
   response->setCorsExposedHeaderNames(cors_exposed_header_names);
+  response->setDidServiceWorkerNavigationPreload(
+      info.did_service_worker_navigation_preload);
   response->setEncodedDataLength(info.encoded_data_length);
 
   SetSecurityStyleAndDetails(url, info, response, report_security_info);