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

chrome/browser/policy/cloud/device_management_service_unittest.cc

Index: chrome/browser/policy/cloud/device_management_service_unittest.cc
diff --git a/chrome/browser/policy/cloud/device_management_service_unittest.cc b/chrome/browser/policy/cloud/device_management_service_unittest.cc
index ae849654d9e07744976fb3c51c1021b3f3281d5a..b83ca80d4cecc682ccc2ba8babd23ad9bd920218 100644
--- a/chrome/browser/policy/cloud/device_management_service_unittest.cc
+++ b/chrome/browser/policy/cloud/device_management_service_unittest.cc
@@ -513,7 +513,7 @@ TEST_F(DeviceManagementServiceTest, CancelDuringCallback) {
 
   // Generate a callback.
   net::URLRequestStatus status(net::URLRequestStatus::SUCCESS, 0);
-  SendResponse(fetcher, status, 500, "");
+  SendResponse(fetcher, status, 500, std::string());
 
   // Job should have been reset.
   EXPECT_FALSE(request_job.get());
@@ -534,7 +534,7 @@ TEST_F(DeviceManagementServiceTest, RetryOnProxyError) {
   // Generate a callback with a proxy failure.
   net::URLRequestStatus status(net::URLRequestStatus::FAILED,
                                net::ERR_PROXY_CONNECTION_FAILED);
-  SendResponse(fetcher, status, 200, "");
+  SendResponse(fetcher, status, 200, std::string());
 
   // Verify that a new URLFetcher was started that bypasses the proxy.
   fetcher = GetFetcher();
@@ -564,7 +564,7 @@ TEST_F(DeviceManagementServiceTest, RetryOnBadResponseFromProxy) {
   // Generate a callback with a valid http response, that was generated by
   // a bad/wrong proxy.
   net::URLRequestStatus status;
-  SendResponse(fetcher, status, 200, "");
+  SendResponse(fetcher, status, 200, std::string());
 
   // Verify that a new URLFetcher was started that bypasses the proxy.
   fetcher = GetFetcher();