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

chrome/test/chromedriver/keycode_text_conversion_x.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/test/chromedriver/keycode_text_conversion.h"
 
 #include <algorithm>
 #include <X11/keysym.h>
 #include <X11/XKBlib.h>
 #include <X11/Xlib.h>
@@ skipping 162 matching lines @@
   }
   XFreeModifiermap(mod_map);
   return found;
 }
 
 }  // namespace
 
 std::string ConvertKeyCodeToText(ui::KeyboardCode key_code, int modifiers) {
   int x_key_code = KeyboardCodeToXKeyCode(key_code);
   if (x_key_code == -1)
-    return "";
+    return std::string();
 
   XEvent event;
   memset(&event, 0, sizeof(XEvent));
   XKeyEvent* key_event = &event.xkey;
   Display* display = ui::GetXDisplay();
   key_event->display = display;
   key_event->keycode = x_key_code;
   if (modifiers & kShiftKeyModifierMask)
     key_event->state |= ShiftMask;
   if (modifiers & kControlKeyModifierMask)
@@ skipping 10 matching lines @@
     key_event->state |= x_modifier;
   }
   if (modifiers & kNumLockKeyModifierMask &&
       GetXModifierMask(display, kNumLockKeyModifierMask, &x_modifier)) {
     key_event->state |= x_modifier;
   }
   key_event->type = KeyPress;
   uint16 character = ui::GetCharacterFromXEvent(&event);
 
   if (!character)
-    return "";
+    return std::string();
   return UTF16ToUTF8(string16(1, character));
 }
 
 bool ConvertCharToKeyCode(
     char16 key,
     ui::KeyboardCode* key_code,
     int* necessary_modifiers) {
   std::string key_string(UTF16ToUTF8(string16(1, key)));
   bool found = false;
   ui::KeyboardCode test_code;
@@ skipping 13 matching lines @@
       found = true;
       break;
     }
   }
   if (found) {
     *key_code = test_code;
     *necessary_modifiers = test_modifiers;
   }
   return found;
 }