Add foundation for trimming the AffiliationDatabase.

components/password_manager/core/browser/facet_manager.cc

 // Copyright 2015 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.
 
 // Note: Read the class comment of AffiliationService for the definition of the
 // terms used below.
 //
 // On-demand fetching strategy
 //
 // A GetAffiliations() request concerning facet X will be served from the cache
@@ skipping 169 matching lines @@
       keep_fresh_until_thresholds_.upper_bound(clock_->Now());
   keep_fresh_until_thresholds_.erase(keep_fresh_until_thresholds_.begin(),
                                      iter_first_non_expired);
 }
 
 bool FacetManager::CanBeDiscarded() const {
   return pending_requests_.empty() &&
          GetMaximumKeepFreshUntilThreshold() <= clock_->Now();
 }
 
+bool FacetManager::CanCachedDataBeDiscarded() const {
+  return GetMaximumKeepFreshUntilThreshold() <= clock_->Now() ||
+         !IsCachedDataFresh();
+}
+
 bool FacetManager::DoesRequireFetch() const {
   return (!pending_requests_.empty() && !IsCachedDataFresh()) ||
          GetNextRequiredFetchTimeDueToPrefetch() <= clock_->Now();
 }
 
 bool FacetManager::IsCachedDataFresh() const {
   return clock_->Now() < GetCacheHardExpiryTime();
 }
 
 bool FacetManager::IsCachedDataNearStale() const {
@@ skipping 35 matching lines @@
       FROM_HERE, base::Bind(request_info.callback, affiliation, true));
 }
 
 // static
 void FacetManager::ServeRequestWithFailure(const RequestInfo& request_info) {
   request_info.callback_task_runner->PostTask(
       FROM_HERE, base::Bind(request_info.callback, AffiliatedFacets(), false));
 }
 
 }  // namespace password_manager