Revert of Replaced cc::SurfaceId::nonce_ with base::UnguessableToken

cc/ipc/local_frame_id_struct_traits.h

Index: cc/ipc/local_frame_id_struct_traits.h
diff --git a/cc/ipc/local_frame_id_struct_traits.h b/cc/ipc/local_frame_id_struct_traits.h
index 514bd4cbeaeb11dd7602dd77d60b2f5deddf41e9..50af9a9cc6414ffeb528599af973404f73323753 100644
--- a/cc/ipc/local_frame_id_struct_traits.h
+++ b/cc/ipc/local_frame_id_struct_traits.h
@@ -7,7 +7,6 @@
 
 #include "cc/ipc/local_frame_id.mojom-shared.h"
 #include "cc/surfaces/local_frame_id.h"
-#include "mojo/common/common_custom_types_struct_traits.h"
 
 namespace mojo {
 
@@ -17,18 +16,13 @@
     return local_frame_id.local_id();
   }
 
-  static const base::UnguessableToken& nonce(
-      const cc::LocalFrameId& local_frame_id) {
+  static uint64_t nonce(const cc::LocalFrameId& local_frame_id) {
     return local_frame_id.nonce();
   }
 
   static bool Read(cc::mojom::LocalFrameIdDataView data,
                    cc::LocalFrameId* out) {
-    base::UnguessableToken nonce;
-    if (!data.ReadNonce(&nonce))
-      return false;
-
-    *out = cc::LocalFrameId(data.local_id(), nonce);
+    *out = cc::LocalFrameId(data.local_id(), data.nonce());
     return true;
   }
 };