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

chrome/browser/google_apis/drive_api_url_generator_unittest.cc

 // Copyright (c) 2013 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/google_apis/drive_api_url_generator.h"
 
 #include "chrome/browser/google_apis/test_util.h"
 #include "googleurl/src/gurl.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 51 matching lines @@
             test_url_generator_.GetChangelistUrl(GURL(), 100).spec());
   EXPECT_EQ("https://localhost/drive/v2/changes?startChangeId=200",
             test_url_generator_.GetChangelistUrl(
                 GURL("https://localhost/drive/v2/changes"), 200).spec());
 }
 
 TEST_F(DriveApiUrlGeneratorTest, GetFilelistUrl) {
   // Use default URL, if |override_url| is empty.
   // Do not add q parameter if |search_string| is empty.
   EXPECT_EQ("https://www.googleapis.com/drive/v2/files",
-            url_generator_.GetFilelistUrl(GURL(), "").spec());
+            url_generator_.GetFilelistUrl(GURL(), std::string()).spec());
 
   // Set q parameter if non-empty |search_string| is given.
   EXPECT_EQ("https://www.googleapis.com/drive/v2/files?q=query",
             url_generator_.GetFilelistUrl(GURL(), "query").spec());
 
   // Use the |override_url| for the base URL if given.
   // The behavior for the |search_string| should be as same as above cases.
-  EXPECT_EQ("https://localhost/drive/v2/files",
-            url_generator_.GetFilelistUrl(
-                GURL("https://localhost/drive/v2/files"), "").spec());
+  EXPECT_EQ(
+      "https://localhost/drive/v2/files",
+      url_generator_.GetFilelistUrl(GURL("https://localhost/drive/v2/files"),
+                                    std::string()).spec());
   EXPECT_EQ("https://localhost/drive/v2/files?q=query",
             url_generator_.GetFilelistUrl(
                 GURL("https://localhost/drive/v2/files"), "query").spec());
 
   // For test server, the given base url should be used,
   // but if |override_url| is given, |override_url| should be used.
   EXPECT_EQ("http://127.0.0.1:12345/drive/v2/files?q=query",
             test_url_generator_.GetFilelistUrl(GURL(), "query").spec());
   EXPECT_EQ("https://localhost/drive/v2/files?q=query",
             test_url_generator_.GetFilelistUrl(
@@ skipping 136 matching lines @@
       test_url_generator_.GetInitiateUploadExistingFileUrl(
           "0Bz0bd074").spec());
   EXPECT_EQ(
       "http://127.0.0.1:12345/upload/drive/v2/files/file%3Afile_id"
       "?uploadType=resumable",
       test_url_generator_.GetInitiateUploadExistingFileUrl(
           "file:file_id").spec());
 }
 
 }  // namespace google_apis