Update from https://crrev.com/320343

base/json/json_value_serializer_unittest.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 <string>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/json/json_reader.h"
@@ skipping 43 matching lines @@
     "   \"some_String\": \"1337\",\n"
     "   \"some_int\": 42,\n"
     "   \"the_list\": [ \"val1\", \"val2\" ]\n"
     "}\n"
     "?!ab\n";
 
 const char kWinLineEnds[] = "\r\n";
 const char kLinuxLineEnds[] = "\n";
 
 // Verifies the generated JSON against the expected output.
-void CheckJSONIsStillTheSame(Value& value) {
+void CheckJSONIsStillTheSame(const Value& value) {
   // Serialize back the output.
   std::string serialized_json;
   JSONStringValueSerializer str_serializer(&serialized_json);
   str_serializer.set_pretty_print(true);
   ASSERT_TRUE(str_serializer.Serialize(value));
   // Unify line endings between platforms.
   ReplaceSubstringsAfterOffset(&serialized_json, 0,
                                kWinLineEnds, kLinuxLineEnds);
   // Now compare the input with the output.
   ASSERT_EQ(kProperJSON, serialized_json);
@@ skipping 413 matching lines @@
   ASSERT_TRUE(PathExists(source_file_path));
   JSONFileValueDeserializer deserializer(source_file_path);
   scoped_ptr<Value> root;
   root.reset(deserializer.Deserialize(NULL, NULL));
   ASSERT_TRUE(root.get());
 }
 
 }  // namespace
 
 }  // namespace base