Add base::UnguessableToken

ipc/ipc_message_utils.h

Index: ipc/ipc_message_utils.h
diff --git a/ipc/ipc_message_utils.h b/ipc/ipc_message_utils.h
index 6712d3ca69363e8a1e48a416304a1e54bb0c55d9..6c5fdf9f3887a22923b8d847ddc1eba116426a9d 100644
--- a/ipc/ipc_message_utils.h
+++ b/ipc/ipc_message_utils.h
@@ -41,6 +41,7 @@ class Time;
 class TimeDelta;
 class TimeTicks;
 struct FileDescriptor;
+struct Nonce;
 
 #if (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_WIN)
 class SharedMemoryHandle;
@@ -667,6 +668,17 @@ struct IPC_EXPORT ParamTraits<base::TimeTicks> {
 };
 
 template <>
+struct IPC_EXPORT ParamTraits<base::Nonce> {
+  typedef base::Nonce param_type;
+  static void GetSize(base::PickleSizer* sizer, const param_type& p);
+  static void Write(base::Pickle* m, const param_type& p);
+  static bool Read(const base::Pickle* m,
+                   base::PickleIterator* iter,
+                   param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
+template <>
 struct ParamTraits<std::tuple<>> {
   typedef std::tuple<> param_type;
   static void GetSize(base::PickleSizer* sizer, const param_type& p) {}