At the moment deserialization happens synchronously on the main thread.
This is fine at the moment because deserialization is fast. However,
future refactorings may affect deserialization time, and may force us
to deserialize in the background. This CL adds a timer to monitor
deserialization time, so that we get a signal if deserialization time
regresses.

R=clemensb@chromium.org

Bug: v8:11862
Change-Id: I18b52c19106b92158cd986492926a24d0d57e6ba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2966389Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75218}