Use host_piece() when comparing web store URL

This change avoids allocating an additional std::string by using the
host_piece() method on GURL instead of using host() when comparing
against another GURL.

Bug: 663729
Change-Id: I3afd3aeccc0ecca4c04a77543adbdb856a78940e
Reviewed-on: https://chromium-review.googlesource.com/1036444
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554914}

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc

@@ -638,7 +638,7 @@ void ChromeResourceDispatcherHostDelegate::OnResponseStarted(
 #if BUILDFLAG(ENABLE_EXTENSIONS)
   GURL webstore_url(extension_urls::GetWebstoreLaunchURL());
   if (request->url().SchemeIsHTTPOrHTTPS() &&
-      request->url().DomainIs(webstore_url.host().c_str())) {
+      request->url().DomainIs(webstore_url.host_piece())) {
     net::HttpResponseHeaders* response_headers = request->response_headers();
     if (response_headers &&
         !response_headers->HasHeaderValue("x-frame-options", "deny") &&