Update declarative shadow dom perf test

For some reason this test was explicitly specifying a slotting mode,
and the imperative API changed from "auto" to "named". No need for
this parameter anyway, so this just removes it.

Bug: 1201402
Change-Id: Ica82b6c58093e0a934f02f2e0de2b2eaa78d91e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2847253
Auto-Submit: Mason Freed <masonf@chromium.org>
Reviewed-by: Wenbin Zhang <wenbinzhang@google.com>
Commit-Queue: Mason Freed <masonf@chromium.org>
Cr-Commit-Position: refs/heads/master@{#875539}
GitOrigin-RevId: 32978c967e017eba0f23d70632bcaf1b42c202a8
diff --git a/perf/expectations.config b/perf/expectations.config
index 5ea5177..6e9bec5 100644
--- a/perf/expectations.config
+++ b/perf/expectations.config
@@ -73,7 +73,6 @@
 crbug.com/1062104 blink_perf.shadow_dom/imperative-api-assigned-slot.html [ Skip ]
 crbug.com/1062104 blink_perf.shadow_dom/imperative-api-insertbefore.html [ Skip ]
 crbug.com/1201402 blink_perf.shadow_dom/imperative-api.html [ Skip ]
-crbug.com/1201402 blink_perf.shadow_dom/declarative-api.html [ Skip ]
 
 # Benchmark: dromaeo
 crbug.com/1050065 [ android-pixel-2 ] dromaeo/http://dromaeo.com?dom-modify [ Skip ]