Add enterprise policy for network time service

components/network_time/network_time_tracker.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 "components/network_time/network_time_tracker.h"
 
 #include <stdint.h>
 #include <string>
 #include <utility>
 
@@ skipping 173 matching lines @@
 void RecordFetchValidHistogram(bool valid) {
   UMA_HISTOGRAM_BOOLEAN("NetworkTimeTracker.UpdateTimeFetchValid", valid);
 }
 
 }  // namespace
 
 // static
 void NetworkTimeTracker::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterDictionaryPref(prefs::kNetworkTimeMapping,
                                    base::MakeUnique<base::DictionaryValue>());
+  registry->RegisterBooleanPref(prefs::kNetworkTimeQueriesEnabled, true);
 }
 
 NetworkTimeTracker::NetworkTimeTracker(
     std::unique_ptr<base::Clock> clock,
     std::unique_ptr<base::TickClock> tick_clock,
     PrefService* pref_service,
     scoped_refptr<net::URLRequestContextGetter> getter)
     : server_url_(kTimeServiceURL),
       max_response_size_(1024),
       backoff_(base::TimeDelta::FromMinutes(kBackoffMinutes)),
@@ skipping 267 matching lines @@
           trigger:
             "A request can be sent to retrieve the current time when the user "
             "encounters an SSL date error, or in the background if Chromium "
             "determines that it doesn't have an accurate timestamp."
           data: "None"
           destination: GOOGLE_OWNED_SERVICE
         }
         policy {
           cookies_allowed: false
           setting: "This feature cannot be disabled by settings."
-          policy_exception_justification: "Not implemented."
+          chrome_policy {
+            NetworkTimeQueriesEnabled {
+                NetworkTimeQueriesEnabled: false
+            }
+          }
         })");
   // This cancels any outstanding fetch.
   time_fetcher_ = net::URLFetcher::Create(url, net::URLFetcher::GET, this,
                                           traffic_annotation);
   if (!time_fetcher_) {
     DVLOG(1) << "tried to make fetch happen; failed";
     return;
   }
   data_use_measurement::DataUseUserData::AttachToFetcher(
       time_fetcher_.get(),
@@ skipping 122 matching lines @@
     timer_.Start(FROM_HERE, delay, this, &NetworkTimeTracker::CheckTime);
   }
 }
 
 bool NetworkTimeTracker::ShouldIssueTimeQuery() {
   // Do not query the time service if not enabled via Variations Service.
   if (!AreTimeFetchesEnabled()) {
     return false;
   }
 
+  // Do not query the time service if queries are disabled by policy.
+  if (!pref_service_->GetBoolean(prefs::kNetworkTimeQueriesEnabled)) {
+    return false;
+  }
+
   // If GetNetworkTime() does not return NETWORK_TIME_AVAILABLE,
   // synchronization has been lost and a query is needed.
   base::Time network_time;
   if (GetNetworkTime(&network_time, nullptr) != NETWORK_TIME_AVAILABLE) {
     return true;
   }
 
   // Otherwise, make the decision at random.
   return base::RandDouble() < RandomQueryProbability();
 }
 
 }  // namespace network_time