Expire appcaches that fail to update for "too long".

content/browser/appcache/appcache.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_APPCACHE_APPCACHE_H_
 #define CONTENT_BROWSER_APPCACHE_APPCACHE_H_
 
 #include <map>
 #include <set>
 #include <vector>
@@ skipping 85 matching lines @@
     if (update_time_ > cache->update_time_)
       return true;
 
     // Tie breaker. Newer caches have a larger cache ID.
     if (update_time_ == cache->update_time_)
       return cache_id_ > cache->cache_id_;
 
     return false;
   }
 
+  // When this version was stored by an update job.
   base::Time update_time() const { return update_time_; }
 
+  // Used to evict caches that fail to update in a reasonable timeframe.
+  base::Time newest_successful_unconditional_update_check_time() { return base::Time(); }

[palmer, 2015/04/21 19:56:34]

In the real implementation, these wouldn't really be base::Time(), right? You'd
store them in fields and persist them to disk?

[michaeln, 2015/04/21 20:20:15]

Just like update_time, the value would stored on disk and the in-memory
representation would be base::Time.

+  base::Time oldest_failed_update_check_time() const; { return base::Time(); }
+
   int64 cache_size() const { return cache_size_; }
 
   void set_update_time(base::Time ticks) { update_time_ = ticks; }
 
   // Initializes the cache with information in the manifest.
   // Do not use the manifest after this call.
   void InitializeWithManifest(AppCacheManifest* manifest);
 
   // Initializes the cache with the information in the database records.
   void InitializeWithDatabaseRecords(
@@ skipping 83 matching lines @@
   AppCacheStorage* storage_;
 
   FRIEND_TEST_ALL_PREFIXES(content::AppCacheTest, InitializeWithManifest);
   FRIEND_TEST_ALL_PREFIXES(content::AppCacheTest, ToFromDatabaseRecords);
   DISALLOW_COPY_AND_ASSIGN(AppCache);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_APPCACHE_APPCACHE_H_