Implement lossy pref behavior for JsonPrefStore.

components/bookmarks/browser/bookmark_storage.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/bookmarks/browser/bookmark_storage.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_util.h"
 #include "base/json/json_file_value_serializer.h"
@@ skipping 128 matching lines @@
   extra_nodes_ = load_extra_callback_.Run(&max_id_);
 }
 
 // BookmarkStorage -------------------------------------------------------------
 
 BookmarkStorage::BookmarkStorage(
     BookmarkModel* model,
     const base::FilePath& profile_path,
     base::SequencedTaskRunner* sequenced_task_runner)
     : model_(model),
-      writer_(profile_path.Append(kBookmarksFileName), sequenced_task_runner),
+      writer_(new base::ImportantFileWriterImpl(
+          profile_path.Append(kBookmarksFileName),
+          sequenced_task_runner)),
       weak_factory_(this) {
   sequenced_task_runner_ = sequenced_task_runner;
-  writer_.set_commit_interval(base::TimeDelta::FromMilliseconds(kSaveDelayMS));
-  sequenced_task_runner_->PostTask(FROM_HERE,
-                                   base::Bind(&BackupCallback, writer_.path()));
+  writer_->set_commit_interval(base::TimeDelta::FromMilliseconds(kSaveDelayMS));
+  sequenced_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&BackupCallback, writer_->path()));
 }
 
 BookmarkStorage::~BookmarkStorage() {
-  if (writer_.HasPendingWrite())
-    writer_.DoScheduledWrite();
+  if (writer_->HasPendingWrite())
+    writer_->DoScheduledWrite();
 }
 
 void BookmarkStorage::LoadBookmarks(
     scoped_ptr<BookmarkLoadDetails> details,
     const scoped_refptr<base::SequencedTaskRunner>& task_runner) {
-  sequenced_task_runner_->PostTask(FROM_HERE,
-                                   base::Bind(&LoadCallback,
-                                              writer_.path(),
-                                              weak_factory_.GetWeakPtr(),
-                                              base::Passed(&details),
-                                              task_runner));
+  sequenced_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&LoadCallback, writer_->path(), weak_factory_.GetWeakPtr(),
+                 base::Passed(&details), task_runner));
 }
 
 void BookmarkStorage::ScheduleSave() {
-  writer_.ScheduleWrite(this);
+  writer_->ScheduleWrite(this);
 }
 
 void BookmarkStorage::BookmarkModelDeleted() {
   // We need to save now as otherwise by the time SaveNow is invoked
   // the model is gone.
-  if (writer_.HasPendingWrite())
+  if (writer_->HasPendingWrite())
     SaveNow();
   model_ = NULL;
 }
 
 bool BookmarkStorage::SerializeData(std::string* output) {
   BookmarkCodec codec;
   scoped_ptr<base::Value> value(codec.Encode(model_));
   JSONStringValueSerializer serializer(output);
   serializer.set_pretty_print(true);
   return serializer.Serialize(*(value.get()));
@@ skipping 10 matching lines @@
   if (!model_ || !model_->loaded()) {
     // We should only get here if we have a valid model and it's finished
     // loading.
     NOTREACHED();
     return false;
   }
 
   scoped_ptr<std::string> data(new std::string);
   if (!SerializeData(data.get()))
     return false;
-  writer_.WriteNow(data.Pass());
+  writer_->WriteNow(data.Pass());
   return true;
 }
 
 }  // namespace bookmarks