Fix a race condition in preference metric reporting.

chrome/browser/managed_mode/managed_user_settings_service.cc

 // Copyright 2013 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 "chrome/browser/managed_mode/managed_user_settings_service.h"
 
 #include "base/callback.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/prefs/json_pref_store.h"
+#include "base/prefs/pref_filter.h"
 #include "base/strings/string_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/managed_mode/managed_mode_url_filter.h"
 #include "chrome/common/chrome_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/user_metrics.h"
 #include "sync/api/sync_change.h"
 #include "sync/api/sync_error_factory.h"
 #include "sync/protocol/sync.pb.h"
 
@@ skipping 31 matching lines @@
     : active_(false), local_settings_(new base::DictionaryValue) {}
 
 ManagedUserSettingsService::~ManagedUserSettingsService() {}
 
 void ManagedUserSettingsService::Init(
     base::FilePath profile_path,
     base::SequencedTaskRunner* sequenced_task_runner,
     bool load_synchronously) {
   base::FilePath path =
       profile_path.Append(chrome::kManagedUserSettingsFilename);
-  PersistentPrefStore* store = new JsonPrefStore(path, sequenced_task_runner);
+  PersistentPrefStore* store = new JsonPrefStore(
+      path, sequenced_task_runner, scoped_ptr<PrefFilter>());
   Init(store);
   if (load_synchronously)
     store_->ReadPrefs();
   else
     store_->ReadPrefsAsync(NULL);
 }
 
 void ManagedUserSettingsService::Init(
     scoped_refptr<PersistentPrefStore> store) {
   DCHECK(!store_);
@@ skipping 299 matching lines @@
 void ManagedUserSettingsService::InformSubscribers() {
   if (!IsReady())
     return;
 
   scoped_ptr<base::DictionaryValue> settings = GetSettings();
   for (std::vector<SettingsCallback>::iterator it = subscribers_.begin();
        it != subscribers_.end(); ++it) {
     it->Run(settings.get());
   }
 }