[devtools] Rebaseline and reeable tests related to crbug.com/1151285.

Tbr: yangguo@chromium.org
Bug: chromium:1151285
Change-Id: Ia5019c6ac2be8a2b908e79ab6d96c2df7dbf8095
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2553542
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830114}

third_party/blink/web_tests/TestExpectations

@@ -2006,9 +2006,6 @@ crbug.com/932343 external/wpt/css/css-pseudo/selection-text-shadow-016.html [ Fa
 
 crbug.com/723741 virtual/threaded/http/tests/devtools/tracing/idle-callback.js [ Failure Crash Pass Timeout ]
 
-# Will be re-enabled and rebaselined once https://crrev.com/c/2552506 lands and rolls.
-crbug.com/1151285 http/tests/devtools/extensions/extensions-api.js [ Failure Pass ]
-
 # Untriaged failures after https://crrev.com/c/543695/.
 # These need to be updated but appear not to be related to that change.
 crbug.com/626703 http/tests/devtools/indexeddb/database-refresh-view.js [ Pass Failure ]

third_party/blink/web_tests/http/tests/devtools/extensions/extensions-api-expected.txt

@@ -19,6 +19,7 @@ RUNNING TEST: extension_testAPI
     }
     languageServices : {
         registerLanguageExtensionPlugin : <function>
+        unregisterLanguageExtensionPlugin : <function>
     }
     network : {
         addRequestHeaders : <function>