[Doodle] Move ttl clamping from fetcher to service

components/doodle/doodle_service.cc

 // Copyright 2017 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 "components/doodle/doodle_service.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "components/doodle/pref_names.h"
 #include "components/prefs/pref_registry.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 
 namespace doodle {
 
+namespace {
+
+const int64_t kMaxTimeToLiveSecs = 30 * 24 * 60 * 60;  // 30 days
+
+}  // namespace
+
 // static
 void DoodleService::RegisterProfilePrefs(PrefRegistrySimple* pref_registry) {
   pref_registry->RegisterDictionaryPref(prefs::kCachedConfig,
                                         new base::DictionaryValue(),
                                         PrefRegistry::LOSSY_PREF);
   pref_registry->RegisterInt64Pref(prefs::kCachedConfigExpiry, 0,
                                    PrefRegistry::LOSSY_PREF);
 }
 
 DoodleService::DoodleService(PrefService* pref_service,
@@ skipping 111 matching lines @@
     const base::Optional<DoodleConfig>& doodle_config) {
   base::TimeDelta download_time = tick_clock_->NowTicks() - start_time;
   DownloadOutcome outcome = HandleNewConfig(state, time_to_live, doodle_config);
   RecordDownloadMetrics(outcome, download_time);
 }
 
 DoodleService::DownloadOutcome DoodleService::HandleNewConfig(
     DoodleState state,
     base::TimeDelta time_to_live,
     const base::Optional<DoodleConfig>& doodle_config) {
+  // Clamp the time-to-live to some reasonable maximum.
+  if (time_to_live.InSeconds() > kMaxTimeToLiveSecs) {
+    time_to_live = base::TimeDelta::FromSeconds(kMaxTimeToLiveSecs);
+    DLOG(WARNING) << "Clamping TTL to " << kMaxTimeToLiveSecs << " seconds!";
+  }
+
   // Handle the case where the new config is already expired.
   bool expired = time_to_live <= base::TimeDelta();
   const base::Optional<DoodleConfig>& new_config =
       expired ? base::nullopt : doodle_config;
 
   // Determine the download outcome *before* updating the cached config.
   DownloadOutcome outcome =
       DetermineDownloadOutcome(cached_config_, new_config, state, expired);
 
   // If the config changed, update our cache and notify observers.
@@ skipping 37 matching lines @@
     pref_service_->ClearPref(prefs::kCachedConfigExpiry);
   }
 }
 
 void DoodleService::DoodleExpired() {
   DCHECK(cached_config_.has_value());
   HandleNewConfig(DoodleState::NO_DOODLE, base::TimeDelta(), base::nullopt);
 }
 
 }  // namespace doodle