Use current navigation url for OnStart cookie query

This was using the previous page's url. Ooops

Bug: 1029959
Change-Id: Ibda0079598698cfebc54c0c579f76f31355284e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1948045Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721530}

chrome/browser/page_load_metrics/observers/subresource_loading_page_load_metrics_observer.cc

@@ -58,7 +58,7 @@ SubresourceLoadingPageLoadMetricsObserver::OnStart(
   navigation_start_ = base::Time::Now();
 
   CheckForCookiesOnURL(navigation_handle->GetWebContents()->GetBrowserContext(),
-                       currently_committed_url);
+                       navigation_handle->GetURL());
   return CONTINUE_OBSERVING;
 }