Add a Dns preresolve interface in //content

chrome/browser/chromeos/login/auth/auth_prewarmer.cc

Index: chrome/browser/chromeos/login/auth/auth_prewarmer.cc
diff --git a/chrome/browser/chromeos/login/auth/auth_prewarmer.cc b/chrome/browser/chromeos/login/auth/auth_prewarmer.cc
index 6ebf6bfa231768c524a921ac57b8ec7ab1bde069..881ec2ec096cbcc983da4b2fb6a5ce629987c0ff 100644
--- a/chrome/browser/chromeos/login/auth/auth_prewarmer.cc
+++ b/chrome/browser/chromeos/login/auth/auth_prewarmer.cc
@@ -97,8 +97,8 @@ void AuthPrewarmer::DoPrewarm() {
   content::BrowserThread::PostTask(
       content::BrowserThread::IO, FROM_HERE,
       base::Bind(&content::PreconnectUrl,
-                 base::RetainedRef(GetRequestContext()), url, url,
-                 kConnectionsNeeded, true,
+                 ProfileHelper::GetSigninProfile()->GetResourceContext(), url,
+                 url, kConnectionsNeeded, true,
                  net::HttpRequestInfo::EARLY_LOAD_MOTIVATED));
   if (!completion_callback_.is_null()) {
     content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,