Replace wstring with string16 in sandbox

sandbox/win/src/named_pipe_dispatcher.h

Index: sandbox/win/src/named_pipe_dispatcher.h
diff --git a/sandbox/win/src/named_pipe_dispatcher.h b/sandbox/win/src/named_pipe_dispatcher.h
index 0d03b2e9db56a691a82dba9b2790d86051b17471..0707284d6efea0b1a61cbbb519c2266d16a1f425 100644
--- a/sandbox/win/src/named_pipe_dispatcher.h
+++ b/sandbox/win/src/named_pipe_dispatcher.h
@@ -6,6 +6,7 @@
 #define SANDBOX_SRC_NAMED_PIPE_DISPATCHER_H__
 
 #include "base/basictypes.h"
+#include "base/strings/string16.h"
 #include "sandbox/win/src/crosscall_server.h"
 #include "sandbox/win/src/sandbox_policy_base.h"
 
@@ -23,7 +24,7 @@ class NamedPipeDispatcher : public Dispatcher {
  private:
   // Processes IPC requests coming from calls to CreateNamedPipeW() in the
   // target.
-  bool CreateNamedPipe(IPCInfo* ipc, std::wstring* name, DWORD open_mode,
+  bool CreateNamedPipe(IPCInfo* ipc, base::string16* name, DWORD open_mode,
                        DWORD pipe_mode, DWORD max_instances,
                        DWORD out_buffer_size, DWORD in_buffer_size,
                        DWORD default_timeout);