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

content/browser/appcache/mock_appcache_storage.cc

Index: content/browser/appcache/mock_appcache_storage.cc
diff --git a/content/browser/appcache/mock_appcache_storage.cc b/content/browser/appcache/mock_appcache_storage.cc
index efac9ba992ea50cd459cee9dc1722d98fd0b7402..a59fe30c437b8707eb684ca1de05179a30c173cc 100644
--- a/content/browser/appcache/mock_appcache_storage.cc
+++ b/content/browser/appcache/mock_appcache_storage.cc
@@ -155,6 +155,12 @@ void MockAppCacheStorage::MakeGroupObsolete(AppCacheGroup* group,
                  response_code));
 }
 
+void MockAppCacheStorage::StoreEvictionTimes(AppCacheGroup* group) {
+  stored_eviction_times_[group->group_id()] =
+      std::make_pair(group->last_full_update_check_time(),
+                     group->first_evictable_error_time());
+}
+
 AppCacheResponseReader* MockAppCacheStorage::CreateResponseReader(
     const GURL& manifest_url, int64 group_id, int64 response_id) {
   if (simulated_reader_)