Replace wstring with string16 in sandbox

sandbox/win/src/window.h

Index: sandbox/win/src/window.h
diff --git a/sandbox/win/src/window.h b/sandbox/win/src/window.h
index e8233e734ee0b78bdb56b15f08e929ee32dc30ec..62fe7c47421be9ee6eb0b0fa233ce25e56b4f2c7 100644
--- a/sandbox/win/src/window.h
+++ b/sandbox/win/src/window.h
@@ -8,6 +8,7 @@
 #include <windows.h>
 #include <string>
 
+#include "base/strings/string16.h"
 #include "sandbox/win/src/sandbox_types.h"
 
 namespace sandbox {
@@ -26,13 +27,13 @@ namespace sandbox {
   ResultCode CreateAltDesktop(HWINSTA winsta, HDESK* desktop);
 
   // Returns the name of a desktop or a window station.
-  std::wstring GetWindowObjectName(HANDLE handle);
+  base::string16 GetWindowObjectName(HANDLE handle);
 
   // Returns the name of the desktop referenced by |desktop|. If a window
   // station is specified, the name is prepended with the window station name,
   // followed by a backslash. This name can be used as the lpDesktop parameter
   // to CreateProcess.
-  std::wstring GetFullDesktopName(HWINSTA winsta, HDESK desktop);
+  base::string16 GetFullDesktopName(HWINSTA winsta, HDESK desktop);
 
 }  // namespace sandbox