stale-while-revalidate experimental implementation.

chrome/browser/predictors/resource_prefetch_predictor.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
 
 #include <map>
 #include <set>
 #include <utility>
 
@@ skipping 228 matching lines @@
   if (response->was_cached())
     return true;
 
   // For non cached responses, we will ensure that the freshness lifetime is
   // some sane value.
   const net::HttpResponseInfo& response_info = response->response_info();
   if (!response_info.headers.get())
     return false;
   base::Time response_time(response_info.response_time);
   response_time += base::TimeDelta::FromSeconds(1);
-  base::TimeDelta freshness = response_info.headers->GetFreshnessLifetime(
-      response_time);
+  base::TimeDelta freshness =
+      response_info.headers->GetFreshnessLifetimes(response_time).fresh;
   return freshness > base::TimeDelta();
 }
 
 // static
 content::ResourceType ResourcePrefetchPredictor::GetResourceTypeFromMimeType(
     const std::string& mime_type,
     content::ResourceType fallback) {
   if (net::IsSupportedImageMimeType(mime_type.c_str()))
     return content::RESOURCE_TYPE_IMAGE;
   else if (net::IsSupportedJavascriptMimeType(mime_type.c_str()))
@@ skipping 952 matching lines @@
     RPP_PREDICTED_HISTOGRAM_PERCENTAGE(
         "PrefetchFromNetworkPercentOfTotalFromNetwork",
         prefetch_network * 100.0 / total_resources_fetched_from_network);
   }
 
 #undef RPP_PREDICTED_HISTOGRAM_PERCENTAGE
 #undef RPP_PREDICTED_HISTOGRAM_COUNTS
 }
 
 }  // namespace predictors