Replace wstring with string16 in sandbox

sandbox/win/src/process_thread_policy.h

Index: sandbox/win/src/process_thread_policy.h
diff --git a/sandbox/win/src/process_thread_policy.h b/sandbox/win/src/process_thread_policy.h
index c35c52b5e6d773fdefc217eb991a48d49f7be731..2871dcaa276b3b660a1f202487644600e26b21da 100644
--- a/sandbox/win/src/process_thread_policy.h
+++ b/sandbox/win/src/process_thread_policy.h
@@ -10,6 +10,7 @@
 #include "sandbox/win/src/policy_low_level.h"
 
 #include "base/basictypes.h"
+#include "base/strings/string16.h"
 #include "sandbox/win/src/crosscall_server.h"
 #include "sandbox/win/src/sandbox_policy.h"
 
@@ -71,8 +72,8 @@ class ProcessPolicy {
   // 'command_line' : The command line passed to the created process.
   static DWORD CreateProcessWAction(EvalResult eval_result,
                                     const ClientInfo& client_info,
-                                    const std::wstring &app_name,
-                                    const std::wstring &command_line,
+                                    const base::string16 &app_name,
+                                    const base::string16 &command_line,
                                     PROCESS_INFORMATION* process_info);
 };