Implement lossy pref behavior for JsonPrefStore.

components/feedback/feedback_report.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/feedback/feedback_report.h"
 
 #include "base/files/file.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_util.h"
 #include "base/files/important_file_writer.h"
@@ skipping 11 matching lines @@
 
 void WriteReportOnBlockingPool(const base::FilePath reports_path,
                                const base::FilePath& file,
                                const std::string& data) {
   DCHECK(reports_path.IsParent(file));
   if (!base::DirectoryExists(reports_path)) {
     base::File::Error error;
     if (!base::CreateDirectoryAndGetError(reports_path, &error))
       return;
   }
-  base::ImportantFileWriter::WriteFileAtomically(file, data);
+  base::ImportantFileWriterImpl::WriteFileAtomically(file, data);
 }
 
 }  // namespace
 
 namespace feedback {
 
 FeedbackReport::FeedbackReport(
     const base::FilePath& path,
     const base::Time& upload_at,
     const std::string& data,
@@ skipping 32 matching lines @@
        !name.empty();
        name = enumerator.Next()) {
     std::string data;
     if (ReadFileToString(name, &data))
       callback.Run(data);
     base::DeleteFile(name, false);
   }
 }
 
 }  // namespace feedback