Replace wstring with string16 in sandbox

sandbox/win/src/crosscall_server.h

Index: sandbox/win/src/crosscall_server.h
diff --git a/sandbox/win/src/crosscall_server.h b/sandbox/win/src/crosscall_server.h
index 2a395077db7d2fed75cde722dbd354c73af4ac17..e75400654120a672832f9436372736e93a97ca84 100644
--- a/sandbox/win/src/crosscall_server.h
+++ b/sandbox/win/src/crosscall_server.h
@@ -9,6 +9,7 @@
 #include <vector>
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "base/strings/string16.h"
 #include "sandbox/win/src/crosscall_params.h"
 
 // This is the IPC server interface for CrossCall: The  IPC for the Sandbox
@@ -112,7 +113,7 @@ class CrossCallParamsEx : public CrossCallParams {
 
   // Gets a parameter that is a string. Returns false if the parameter does not
   // exist.
-  bool GetParameterStr(uint32 index, std::wstring* string);
+  bool GetParameterStr(uint32 index, base::string16* string);
 
   // Gets a parameter that is an in/out buffer. Returns false is the parameter
   // does not exist or if the size of the actual parameter is not equal to the