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

net/url_request/url_request_throttler_simulation_unittest.cc

Index: net/url_request/url_request_throttler_simulation_unittest.cc
diff --git a/net/url_request/url_request_throttler_simulation_unittest.cc b/net/url_request/url_request_throttler_simulation_unittest.cc
index 3a5a39979bdbe513be21e6c2adb0dc59c4df4652..cbb8be874e450c28c594025d70912656e8cca4bc 100644
--- a/net/url_request/url_request_throttler_simulation_unittest.cc
+++ b/net/url_request/url_request_throttler_simulation_unittest.cc
@@ -297,11 +297,9 @@ class Server : public DiscreteTimeSimulation::Actor {
 // Mock throttler entry used by Requester class.
 class MockURLRequestThrottlerEntry : public URLRequestThrottlerEntry {
  public:
-  explicit MockURLRequestThrottlerEntry(
-      URLRequestThrottlerManager* manager)
-      : URLRequestThrottlerEntry(manager, ""),
-        mock_backoff_entry_(&backoff_policy_) {
-  }
+  explicit MockURLRequestThrottlerEntry(URLRequestThrottlerManager* manager)
+      : URLRequestThrottlerEntry(manager, std::string()),
+        mock_backoff_entry_(&backoff_policy_) {}
 
   virtual const BackoffEntry* GetBackoffEntry() const OVERRIDE {
     return &mock_backoff_entry_;
@@ -433,7 +431,7 @@ class Requester : public DiscreteTimeSimulation::Actor {
       if (!throttler_entry_->ShouldRejectRequest(server_->mock_request())) {
         int status_code = server_->HandleRequest();
         MockURLRequestThrottlerHeaderAdapter response_headers(status_code);
-        throttler_entry_->UpdateWithResponse("", &response_headers);
+        throttler_entry_->UpdateWithResponse(std::string(), &response_headers);
 
         if (status_code == 200) {
           if (results_)