Always persist data to disk after 60s from the receiving update request.

net/http/http_server_properties_manager.cc

 // Copyright 2014 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 "net/http/http_server_properties_manager.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 761 matching lines @@
   if (detected_corrupted_prefs)
     ScheduleUpdatePrefsOnNetworkThread(DETECTED_CORRUPTED_PREFS);
 }
 
 //
 // Update Preferences with data from the cached data.
 //
 void HttpServerPropertiesManager::ScheduleUpdatePrefsOnNetworkThread(
     Location location) {
   DCHECK(network_task_runner_->RunsTasksOnCurrentThread());
-  // Cancel pending updates, if any.
-  network_prefs_update_timer_->Stop();
+  // Cancel the new update if there's one scheduled already.

[Ryan Hamilton, 2016/12/06 22:24:15]

This comment might be clearer if it were:

// Do not schedule a new update if there is already one scheduled.

+  if (network_prefs_update_timer_->IsRunning())
+    return;
+
   StartPrefsUpdateTimerOnNetworkThread(
       base::TimeDelta::FromMilliseconds(kUpdatePrefsDelayMs));
   // TODO(rtenneti): Delete the following histogram after collecting some data.
   UMA_HISTOGRAM_ENUMERATION("Net.HttpServerProperties.UpdatePrefs", location,
                             HttpServerPropertiesManager::NUM_LOCATIONS);
 }
 
 void HttpServerPropertiesManager::StartPrefsUpdateTimerOnNetworkThread(
     base::TimeDelta delay) {
   DCHECK(network_task_runner_->RunsTasksOnCurrentThread());
@@ skipping 228 matching lines @@
   setting_prefs_ = true;
   pref_delegate_->SetServerProperties(http_server_properties_dict);
   setting_prefs_ = false;
 
   // Note that |completion| will be fired after we have written everything to
   // the Preferences, but likely before these changes are serialized to disk.
   // This is not a problem though, as JSONPrefStore guarantees that this will
   // happen, pretty soon, and even in the case we shut down immediately.
   if (!completion.is_null())
     completion.Run();
+
+  // Reset the update timer if it's still running.
+  if (network_prefs_update_timer_->IsRunning())
+    network_prefs_update_timer_->Stop();

[Ryan Hamilton, 2016/12/06 22:24:15]

I don't' think this is thread safe since this timer, I thought, was on the
network thread but here we're touching it on the prefs thread.

 }
 
 void HttpServerPropertiesManager::SaveAlternativeServiceToServerPrefs(
     const AlternativeServiceInfoVector* alternative_service_info_vector,
     base::DictionaryValue* server_pref_dict) {
   if (!alternative_service_info_vector ||
       alternative_service_info_vector->empty()) {
     return;
   }
   std::unique_ptr<base::ListValue> alternative_service_list(
@@ skipping 73 matching lines @@
                                                        quic_servers_dict);
 }
 
 void HttpServerPropertiesManager::OnHttpServerPropertiesChanged() {
   DCHECK(pref_task_runner_->RunsTasksOnCurrentThread());
   if (!setting_prefs_)
     ScheduleUpdateCacheOnPrefThread();
 }
 
 }  // namespace net