Convert JsonWriter::Write to taking a const ref for the in-param

extensions/browser/value_store/leveldb_value_store.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 "extensions/browser/value_store/leveldb_value_store.h"
 
 #include "base/files/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
@@ skipping 371 matching lines @@
     if (!old_value || !old_value->Equals(&value)) {
       changes->push_back(
           ValueStoreChange(key, old_value.release(), value.DeepCopy()));
     } else {
       write_new_value = false;
     }
   }
 
   if (write_new_value) {
     std::string value_as_json;
-    if (!base::JSONWriter::Write(&value, &value_as_json))
+    if (!base::JSONWriter::Write(value, &value_as_json))
       return Error::Create(OTHER_ERROR, kCannotSerialize, util::NewKey(key));
     batch->Put(key, value_as_json);
   }
 
   return util::NoError();
 }
 
 scoped_ptr<ValueStore::Error> LeveldbValueStore::WriteToDb(
     leveldb::WriteBatch* batch) {
   leveldb::Status status = db_->Write(leveldb::WriteOptions(), batch);
@@ skipping 28 matching lines @@
   CHECK(!status.ok());
   CHECK(!status.IsNotFound());  // not an error
 
   std::string message = status.ToString();
   // The message may contain |db_path_|, which may be considered sensitive
   // data, and those strings are passed to the extension, so strip it out.
   ReplaceSubstringsAfterOffset(&message, 0u, db_path_.AsUTF8Unsafe(), "...");
 
   return Error::Create(CORRUPTION, message, key.Pass());
 }