Implement lossy pref behavior for JsonPrefStore.

ui/app_list/search/dictionary_data_store.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 "ui/app_list/search/dictionary_data_store.h"
 
 #include "base/callback.h"
+#include "base/files/important_file_writer.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/logging.h"
 #include "base/sequenced_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_runner_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/values.h"
 
 namespace app_list {
 
 DictionaryDataStore::DictionaryDataStore(const base::FilePath& data_file,
                                          base::SequencedWorkerPool* worker_pool)
     : data_file_(data_file), worker_pool_(worker_pool) {
   std::string token("app-launcher-data-store");
   token.append(data_file.AsUTF8Unsafe());
 
   // Uses a SKIP_ON_SHUTDOWN file task runner because losing a couple
   // associations is better than blocking shutdown.
   file_task_runner_ = worker_pool->GetSequencedTaskRunnerWithShutdownBehavior(
       worker_pool->GetNamedSequenceToken(token),
       base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
   writer_.reset(
-      new base::ImportantFileWriter(data_file, file_task_runner_.get()));
+      new base::ImportantFileWriterImpl(data_file, file_task_runner_.get()));
 
   cached_dict_.reset(new base::DictionaryValue);
 }
 
 DictionaryDataStore::~DictionaryDataStore() {
   Flush(OnFlushedCallback());
 }
 
 void DictionaryDataStore::Flush(const OnFlushedCallback& on_flushed) {
   if (writer_->HasPendingWrite())
@@ skipping 37 matching lines @@
   return make_scoped_ptr(return_dict);
 }
 
 bool DictionaryDataStore::SerializeData(std::string* data) {
   JSONStringValueSerializer serializer(data);
   serializer.set_pretty_print(true);
   return serializer.Serialize(*cached_dict_.get());
 }
 
 }  // namespace app_list