GitLab

Remove a test fixture trying to turn on the flag
"EmbedderCSPEnforcement". It doesn't exist anymore.

We got:
```
  RuntimeEnabledFeature not recognized: EmbedderCSPEnforcement
```


Bug: None
Change-Id: I703055949a6665aef5c089af17cf2ae50c3b2bec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2612855
Auto-Submit: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Camille Lamy <clamy@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841465}