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

chrome/test/perf/feature_startup_test.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/file_util.h"
 #include "base/path_service.h"
 #include "base/perftimer.h"
 #include "base/stringprintf.h"
 #include "base/time.h"
 #include "chrome/app/chrome_command_ids.h"
@@ skipping 20 matching lines @@
   virtual void SetUp() {}
   virtual void TearDown() {}
 
   static const int kNumCycles = 5;
 
   void PrintTimings(const char* label, TimeDelta timings[kNumCycles],
                     bool important) {
     std::string times;
     for (int i = 0; i < kNumCycles; ++i)
       base::StringAppendF(&times, "%.2f,", timings[i].InMillisecondsF());
-    perf_test::PrintResultList("new_tab", "", label, times, "ms", important);
+    perf_test::PrintResultList(
+        "new_tab", std::string(), label, times, "ms", important);
   }
 
   void InitProfile(UITestBase::ProfileType profile_type) {
     profile_type_ = profile_type;
 
     // Install the location of the test profile file.
     set_template_user_data(UITest::ComputeTypicalUserDataSource(
         profile_type));
   }
 
@@ skipping 138 matching lines @@
                  false /* not important */,
                  UITestBase::COMPLEX_THEME);
 }
 
 // FLAKY: http://crbug.com/69940
 TEST_F(NewTabUIStartupTest, DISABLED_NewTabTimingTestsCold) {
   RunNewTabTimingTest();
 }
 
 }  // namespace