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

net/http/http_server_properties_manager.cc

Index: net/http/http_server_properties_manager.cc
diff --git a/net/http/http_server_properties_manager.cc b/net/http/http_server_properties_manager.cc
index 4d364b6699a72a3a548a27c8b19a8a8f81370654..9a94d69bb043295a072d38690ed77bf67e2f1b9c 100644
--- a/net/http/http_server_properties_manager.cc
+++ b/net/http/http_server_properties_manager.cc
@@ -779,8 +779,10 @@ void HttpServerPropertiesManager::UpdateCacheFromPrefsOnNetworkThread(
 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.
@@ -1029,6 +1031,10 @@ void HttpServerPropertiesManager::UpdatePrefsOnPrefThread(
   // 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(