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

cc/ipc/local_frame_id.mojom

Index: cc/ipc/local_frame_id.mojom
diff --git a/cc/ipc/local_frame_id.mojom b/cc/ipc/local_frame_id.mojom
index feca9b0fcc1471e96d1d499078e8bd1108df8eac..6b25b6b7da302c475b74d0fe7f93769838be2d28 100644
--- a/cc/ipc/local_frame_id.mojom
+++ b/cc/ipc/local_frame_id.mojom
@@ -3,14 +3,13 @@
 // found in the LICENSE file.
 
 module cc.mojom;
+import "mojo/common/common_custom_types.mojom";
 
 struct LocalFrameId {
   // An identifier allocated by the client uniquely identifying a surface within
   // a client process.
   uint32 local_id;
 
-  // A cryptographically secure random int chosen to make the LocalFrameId
-  // unguessable by other clients.
-  uint64 nonce;
+  mojo.common.mojom.UnguessableToken nonce;
 };