Add expiration policy, code to check it, and a test.

components/offline_pages/background/offliner_policy.h

 // Copyright 2016 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.
 
 #ifndef COMPONENTS_OFFLINE_PAGES_BACKGROUND_OFFLINER_POLICY_H_
 #define COMPONENTS_OFFLINE_PAGES_BACKGROUND_OFFLINER_POLICY_H_
 
 namespace {
 const int kMaxRetries = 2;
 const int kBackgroundTimeBudgetSeconds = 170;
 const int kSinglePageTimeBudgetSeconds = 120;
 const int kMinimumBatteryPercentageForNonUserRequestOfflining = 50;
+const int kPageExpirationTimeInSeconds = 60 * 60 * 24 * 7;
 }  // namespace
 
 namespace offline_pages {
 
 // Policy for the Background Offlining system.  Some policy will belong to the
 // RequestCoordinator, some to the RequestQueue, and some to the Offliner.
 class OfflinerPolicy {
  public:
   OfflinerPolicy()
       : prefer_untried_requests_(false),
@@ skipping 28 matching lines @@
   int GetMaxRetries() const { return kMaxRetries; }
 
   bool PowerRequiredForUserRequestedPage() const { return false; }
 
   bool PowerRequiredForNonUserRequestedPage() const { return true; }
 
   bool UnmeteredNetworkRequiredForUserRequestedPage() const { return false; }
 
   bool UnmeteredNetworkRequiredForNonUserRequestedPage() const { return true; }
 
-  int BatteryPercentageRequiredForUserRequestedPage() const { return 50; }
+  int BatteryPercentageRequiredForUserRequestedPage() const { return 0; }
 
   // This is so low because we require the device to be plugged in and charging.
   // If we decide to allow non-user requested pages when not plugged in, we
   // should raise this somewhat higher.
   int BatteryPercentageRequiredForNonUserRequestedPage() const { return 25; }
 
   // How many seconds to keep trying new pages for, before we give up,  and
   // return to the scheduler.
   int GetBackgroundProcessingTimeBudgetSeconds() const {
     return kBackgroundTimeBudgetSeconds;
   }
 
   // How long do we allow a page to load before giving up on it
   int GetSinglePageTimeBudgetInSeconds() const {
     return kSinglePageTimeBudgetSeconds;
   }
 
+  // How long we allow requests to remain in the system before giving up.
+  int GetPageExpirationTimeInSeconds() const {

[dougarnett, 2016/07/27 15:45:13]

Actually seems to be "Request" expiration rather than "Page" expiration

[Pete Williamson, 2016/07/27 17:20:06]

Done.

+    return kPageExpirationTimeInSeconds;
+  }
+
   // How much battery must we have before fetching a page not explicitly
   // requested by the user?
   int GetMinimumBatteryPercentageForNonUserRequestOfflining() const {
     return kMinimumBatteryPercentageForNonUserRequestOfflining;
   }
 
  private:
   bool prefer_untried_requests_;
   bool prefer_earlier_requests_;
   bool retry_count_is_more_important_than_recency_;
 };
 }
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_OFFLINER_POLICY_H_