[roll] Roll fuchsia [scenic] Refactor frame predictor logic.

This is intended to improve clarity without affecting behavior.

Original-Bug: 413800511
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1272823
Original-Revision: 55949a71dfd989f5bb9e0a899fab913799b02df7
GitOrigin-RevId: 3896038aa49462d03634743be598622d3e7eb3a4
Change-Id: Iccee63d96bda3213624aeb100ada60252b0a3e9e
diff --git a/stem b/stem
index fbe04f5..a7db43b 100644
--- a/stem
+++ b/stem
@@ -8,7 +8,7 @@
              root=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="24100aeb5c1343eef44931d14a85ec7535a1448d"
+             revision="55949a71dfd989f5bb9e0a899fab913799b02df7"
              />
   </imports>
   <projects>