Add GetExpirationTimes() to HttpResponseHeader.

webkit/browser/appcache/appcache_update_job.cc

Index: webkit/browser/appcache/appcache_update_job.cc
diff --git a/webkit/browser/appcache/appcache_update_job.cc b/webkit/browser/appcache/appcache_update_job.cc
index 17e3bef6da644a90a10eab2081ed9ee41f2a8523..6d4d5058b45f28812a9dca629c46e86b28714797 100644
--- a/webkit/browser/appcache/appcache_update_job.cc
+++ b/webkit/browser/appcache/appcache_update_job.cc
@@ -1193,10 +1193,11 @@ void AppCacheUpdateJob::OnResponseInfoLoaded(
     const std::string name = "vary";
     std::string value;
     void* iter = NULL;
-    if (!http_info->headers.get() ||
-        http_info->headers->RequiresValidation(http_info->request_time,
-                                               http_info->response_time,
-                                               base::Time::Now()) ||
+    base::Time freshness_expiry =
+        http_info->headers ? base::Time() :
+        http_info->headers->GetFreshnessExpiry(http_info->request_time,
+                                               http_info->response_time);
+    if (freshness_expiry <= base::Time::Now() ||
         http_info->headers->EnumerateHeader(&iter, name, &value)) {
       LoadFromNewestCacheFailed(url, response_info);
     } else {