Replace wstring with string16 in sandbox

sandbox/win/sandbox_poc/pocdll/spyware.cc

 // Copyright (c) 2006-2009 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 <string>
 #include "sandbox/win/sandbox_poc/pocdll/exports.h"
 #include "sandbox/win/sandbox_poc/pocdll/utils.h"
 
 // This file contains the tests used to verify the security of the system by
 // using some spying techniques.
 
 void POCDLL_API TestSpyKeys(HANDLE log) {
   HandleToFile handle2file;
   FILE *output = handle2file.Translate(log, "w");
 
   if (RegisterHotKey(NULL, 1, 0, 0x42)) {
     fprintf(output, "[GRANTED] successfully registered hotkey\r\n");
     UnregisterHotKey(NULL, 1);
   } else {
     fprintf(output, "[BLOCKED] Failed to register hotkey. Error = %d\r\n",
             ::GetLastError());
   }
 
   fprintf(output, "[INFO] Logging keystrokes for 15 seconds\r\n");
   fflush(output);
-  std::wstring logged;
+  base::string16 logged;
   DWORD tick = ::GetTickCount() + 15000;
   while (tick > ::GetTickCount()) {
     for (int i = 0; i < 256; ++i) {
       if (::GetAsyncKeyState(i) & 1) {
         if (i >=  VK_SPACE && i <= 0x5A /*VK_Z*/) {
           logged.append(1, static_cast<wchar_t>(i));
         } else {
           logged.append(1, '?');
         }
       }
@@ skipping 20 matching lines @@
       if (::GetPixel(screen_dc, x, y) != pixel_color) {
         fprintf(output, "[GRANTED] Read pixel on screen\r\n");
         return;
       }
     }
   }
 
   fprintf(output, "[BLOCKED] Read pixel on screen. Error = %d\r\n",
           ::GetLastError());
 }