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

chrome/test/chromedriver/server/http_handler_unittest.cc

 // Copyright (c) 2013 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/bind.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
@@ skipping 56 matching lines @@
   request.method = "post";
   request.path = "/base/session";
   net::HttpServerResponseInfo response;
   handler.Handle(request, base::Bind(&OnResponse, &response));
   ASSERT_EQ(net::HTTP_OK, response.status_code());
   base::DictionaryValue body;
   body.SetInteger("status", kOk);
   body.SetInteger("value", 1);
   body.SetString("sessionId", "session_id");
   std::string json;
-  base::JSONWriter::Write(&body, &json);
+  base::JSONWriter::Write(body, &json);
   ASSERT_EQ(json, response.body());
 }
 
 TEST(HttpHandlerTest, HandleInvalidPost) {
   HttpHandler handler("/");
   handler.command_map_->push_back(
       CommandMapping(kPost, "path", base::Bind(&DummyCommand, Status(kOk))));
   net::HttpServerRequestInfo request;
   request.method = "post";
   request.path = "/path";
@@ skipping 24 matching lines @@
   request.method = "post";
   request.path = "/path";
   net::HttpServerResponseInfo response;
   handler.Handle(request, base::Bind(&OnResponse, &response));
   ASSERT_EQ(net::HTTP_OK, response.status_code());
   base::DictionaryValue body;
   body.SetInteger("status", kOk);
   body.SetInteger("value", 1);
   body.SetString("sessionId", "session_id");
   std::string json;
-  base::JSONWriter::Write(&body, &json);
+  base::JSONWriter::Write(body, &json);
   ASSERT_EQ(json, response.body());
 }
 
 TEST(MatchesCommandTest, DiffMethod) {
   CommandMapping command(kPost, "path", base::Bind(&DummyCommand, Status(kOk)));
   std::string session_id;
   base::DictionaryValue params;
   ASSERT_FALSE(internal::MatchesCommand(
       "get", "path", command, &session_id, &params));
   ASSERT_TRUE(session_id.empty());
@@ skipping 32 matching lines @@
   ASSERT_TRUE(internal::MatchesCommand(
       "post", "path/1/space/2/3", command, &session_id, &params));
   ASSERT_EQ("1", session_id);
   ASSERT_EQ(2u, params.size());
   std::string param;
   ASSERT_TRUE(params.GetString("a", &param));
   ASSERT_EQ("2", param);
   ASSERT_TRUE(params.GetString("b", &param));
   ASSERT_EQ("3", param);
 }