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

chrome/test/webdriver/keycode_text_conversion_gtk.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 "chrome/test/webdriver/keycode_text_conversion.h"
 
 #include <gdk/gdk.h>
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/automation_constants.h"
 #include "ui/base/keycodes/keyboard_code_conversion_gtk.h"
 
 namespace webdriver {
 
 std::string ConvertKeyCodeToText(ui::KeyboardCode key_code, int modifiers) {
   // |gdk_keyval_to_upper| does not convert some keys like '1' to '!', so
   // provide |ui::GdkKeyCodeForWindowsKeyCode| with our shift state as well,
   // which will do basic conversions like it for us.
   guint gdk_key_code = ui::GdkKeyCodeForWindowsKeyCode(
       key_code, modifiers & automation::kShiftKeyMask);
   if (modifiers & automation::kShiftKeyMask)
     gdk_key_code = gdk_keyval_to_upper(gdk_key_code);
   guint32 unicode_char = gdk_keyval_to_unicode(gdk_key_code);
   if (!unicode_char)
-    return "";
+    return std::string();
   gchar buffer[6];
   gint length = g_unichar_to_utf8(unicode_char, buffer);
   return std::string(buffer, length);
 }
 
 // Converts a character to the key code and modifier set that would
 // produce the character using the given keyboard layout.
 bool ConvertCharToKeyCode(
     char16 key, ui::KeyboardCode* key_code, int *necessary_modifiers) {
   guint gdk_key_code = gdk_unicode_to_keyval(key);
@@ skipping 20 matching lines @@
 
   if (is_special_symbol || key_utf32 != g_unichar_tolower(key_utf32))
     *necessary_modifiers = automation::kShiftKeyMask;
   ui::KeyboardCode code = ui::WindowsKeyCodeForGdkKeyCode(gdk_key_code);
   if (code != ui::VKEY_UNKNOWN)
     *key_code = code;
   return code != ui::VKEY_UNKNOWN;
 }
 
 }  // namespace webdriver