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

chrome/browser/policy/cloud/cloud_policy_service_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 "chrome/browser/policy/cloud/cloud_policy_service.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "chrome/browser/policy/cloud/cloud_policy_constants.h"
 #include "chrome/browser/policy/cloud/mock_cloud_policy_client.h"
@@ skipping 100 matching lines @@
   // Store reloads policy, callback gets triggered.
   store_.policy_.reset(new em::PolicyData());
   store_.policy_->set_request_token("token");
   store_.policy_->set_device_id("device-id");
   EXPECT_CALL(*this, OnPolicyRefresh(true)).Times(1);
   store_.NotifyStoreLoaded();
 }
 
 TEST_F(CloudPolicyServiceTest, RefreshPolicyNotRegistered) {
   // Clear the token so the client is not registered.
-  client_.SetDMToken("");
+  client_.SetDMToken(std::string());
 
   EXPECT_CALL(client_, FetchPolicy()).Times(0);
   EXPECT_CALL(*this, OnPolicyRefresh(false)).Times(1);
   service_.RefreshPolicy(base::Bind(&CloudPolicyServiceTest::OnPolicyRefresh,
                                     base::Unretained(this)));
 }
 
 TEST_F(CloudPolicyServiceTest, RefreshPolicyClientError) {
   testing::InSequence seq;
 
@@ skipping 96 matching lines @@
   testing::Mock::VerifyAndClearExpectations(&observer);
 
   // Now, the next time the store is loaded, the observer should not be called
   // again.
   EXPECT_CALL(observer, OnInitializationCompleted(&service_)).Times(0);
   store_.NotifyStoreLoaded();
   service_.RemoveObserver(&observer);
 }
 
 }  // namespace policy