Add base::UnguessableToken

mojo/common/common_custom_types_struct_traits.h

Index: mojo/common/common_custom_types_struct_traits.h
diff --git a/mojo/common/common_custom_types_struct_traits.h b/mojo/common/common_custom_types_struct_traits.h
index 5244cf7a2a6108280136a03f9a3bc385c49a5cb2..be4c6a6b8ec301639c079c72e5ba2555dcd3c67c 100644
--- a/mojo/common/common_custom_types_struct_traits.h
+++ b/mojo/common/common_custom_types_struct_traits.h
@@ -5,6 +5,7 @@
 #ifndef MOJO_COMMON_COMMON_CUSTOM_TYPES_STRUCT_TRAITS_H_
 #define MOJO_COMMON_COMMON_CUSTOM_TYPES_STRUCT_TRAITS_H_
 
+#include "base/nonce_token.h"
 #include "base/version.h"
 #include "mojo/common/common_custom_types.mojom-shared.h"
 
@@ -24,6 +25,35 @@ struct StructTraits<mojo::common::mojom::VersionDataView, base::Version> {
 };
 
 template <>
+struct StructTraits<mojo::common::mojom::NonceTokenDataView, base::NonceToken> {
+  static uint64_t high(const base::NonceToken& token) {
+    CHECK(token);
+    uint64_t high, low;
+    token.Serialize(&high, &low);
+    return high;
+  }
+
+  static uint64_t low(const base::NonceToken& token) {
+    CHECK(token);
+    uint64_t high, low;
+    token.Serialize(&high, &low);
+    return low;
+  }
+
+  static bool Read(mojo::common::mojom::NonceTokenDataView data,
+                   base::NonceToken* out) {
+    uint64_t high = data.high();
+    uint64_t low = data.low();
+
+    if (base::NonceToken::IsZeroData(high, low))
+      return false;
+
+    *out = base::NonceToken::Deserialize(high, low);
+    return true;
+  }
+};
+
+template <>
 struct StructTraits<mojo::common::mojom::TimeDeltaDataView, base::TimeDelta> {
   static int64_t microseconds(const base::TimeDelta& delta) {
     return delta.InMicroseconds();