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

base/nix/mime_util_xdg.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/nix/mime_util_xdg.h"
 
 #include <cstdlib>
 #include <list>
 #include <map>
 #include <vector>
@@ skipping 326 matching lines @@
     if (size + info->threshold < info->size)
       return info->size - size - info->threshold;
     if (size > info->size + info->threshold)
       return size - info->size - info->threshold;
     return 0;
   }
 }
 
 std::string IconTheme::ReadLine(FILE* fp) {
   if (!fp)
-    return "";
+    return std::string();
 
-  std::string result = "";
+  std::string result;
   const size_t kBufferSize = 100;
   char buffer[kBufferSize];
   while ((fgets(buffer, kBufferSize - 1, fp)) != NULL) {
     result += buffer;
     size_t len = result.length();
     if (len == 0)
       break;
     char end = result[len - 1];
     if (end == '\n' || end == '\0')
       break;
@@ skipping 286 matching lines @@
       icon_file = LookupIconInDefaultTheme(icon_names[i], size);
       if (!icon_file.empty())
         return icon_file;
     }
   }
   return FilePath();
 }
 
 }  // namespace nix
 }  // namespace base