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

ipc/ipc_message_utils.cc

 // Copyright (c) 2012 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 "ipc/ipc_message_utils.h"
 
 #include "base/files/file_path.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/nullable_string16.h"
@@ skipping 433 matching lines @@
   int type;
   if (!ReadParam(m, iter, &type) || type != base::Value::TYPE_DICTIONARY)
     return false;
 
   return ReadDictionaryValue(m, iter, r, 0);
 }
 
 void ParamTraits<base::DictionaryValue>::Log(const param_type& p,
                                              std::string* l) {
   std::string json;
-  base::JSONWriter::Write(&p, &json);
+  base::JSONWriter::Write(p, &json);
   l->append(json);
 }
 
 #if defined(OS_POSIX)
 void ParamTraits<base::FileDescriptor>::Write(Message* m, const param_type& p) {
   const bool valid = p.fd >= 0;
   WriteParam(m, valid);
 
   if (!valid)
     return;
@@ skipping 61 matching lines @@
     const Message* m, PickleIterator* iter, param_type* r) {
   int type;
   if (!ReadParam(m, iter, &type) || type != base::Value::TYPE_LIST)
     return false;
 
   return ReadListValue(m, iter, r, 0);
 }
 
 void ParamTraits<base::ListValue>::Log(const param_type& p, std::string* l) {
   std::string json;
-  base::JSONWriter::Write(&p, &json);
+  base::JSONWriter::Write(p, &json);
   l->append(json);
 }
 
 void ParamTraits<base::NullableString16>::Write(Message* m,
                                                 const param_type& p) {
   WriteParam(m, p.string());
   WriteParam(m, p.is_null());
 }
 
 bool ParamTraits<base::NullableString16>::Read(const Message* m,
@@ skipping 282 matching lines @@
   return result;
 }
 
 void ParamTraits<MSG>::Log(const param_type& p, std::string* l) {
   l->append("<MSG>");
 }
 
 #endif  // OS_WIN
 
 }  // namespace IPC