Rewrite std::string("") to std::string(), Linux edition.

chrome/renderer/automation/automation_renderer_helper_browsertest.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 "base/command_line.h"
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/md5.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
@@ skipping 66 matching lines @@
       "</body>";
   LoadHTML(kThreeBoxesRTLHTML);
   std::vector<unsigned char> png_data;
   std::string error_msg;
   ASSERT_TRUE(AutomationRendererHelper(view_).SnapshotEntirePage(
       view_->GetWebView(), &png_data, &error_msg)) << error_msg;
   CompareSnapshot(png_data, kThreeBoxesMD5);
 }
 
 TEST_F(AutomationRendererHelperTest, ScriptChain) {
-  ScriptEvaluationRequest request("({'result': 10})", "");
-  ScriptEvaluationRequest request_plus1(
-      "({'result': arguments[0].result + 1})", "");
+  ScriptEvaluationRequest request("({'result': 10})", std::string());
+  ScriptEvaluationRequest request_plus1("({'result': arguments[0].result + 1})",
+                                        std::string());
   std::vector<ScriptEvaluationRequest> script_chain;
   script_chain.push_back(request);
   script_chain.push_back(request_plus1);
   script_chain.push_back(request_plus1);
 
   AutomationRendererHelper helper(view_);
   scoped_ptr<base::DictionaryValue> value;
   std::string error;
   ASSERT_TRUE(helper.EvaluateScriptChain(script_chain, &value, &error));
   int result;
   ASSERT_TRUE(value->GetInteger("result", &result));
   EXPECT_EQ(12, result);
 }
 
 TEST_F(AutomationRendererHelperTest, ScriptChainError) {
-  ScriptEvaluationRequest request("({'result': 10})", "");
+  ScriptEvaluationRequest request("({'result': 10})", std::string());
   ScriptEvaluationRequest error_request(
       "({'result': arguments[0].result + 1, 'error': {'msg': 'some msg'}})",
-      "");
+      std::string());
   std::vector<ScriptEvaluationRequest> script_chain;
   script_chain.push_back(request);
   script_chain.push_back(error_request);
   script_chain.push_back(request);
 
   AutomationRendererHelper helper(view_);
   scoped_ptr<base::DictionaryValue> result;
   std::string error;
   ASSERT_FALSE(helper.EvaluateScriptChain(script_chain, &result, &error));
   scoped_ptr<base::Value> value(base::JSONReader::Read(error));
   base::DictionaryValue* dict;
   ASSERT_TRUE(value->GetAsDictionary(&dict));
   std::string msg;
   ASSERT_TRUE(dict->GetString("msg", &msg));
   EXPECT_STREQ("some msg", msg.c_str());
 }