Reenabling mobile_throttling tests

Reenabling the tests that were disabled on this CL
2580134: [Loc] Changing mobile throttling settings webtest to match
frontend | https://chromium-review.googlesource.com/c/chromium/src/+/2580134

Bug: 1136655
Change-Id: I10a6a65637ecfe99254e4cc1ce1df19b558ab2c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2582535Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Vidal Diazleal <vidorteg@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#836178}

third_party/blink/web_tests/TestExpectations

@@ -2327,9 +2327,6 @@ crbug.com/1029514 external/wpt/html/semantics/embedded-content/the-video-element
 # css-pseudo-4 opacity not applied to ::first-line
 crbug.com/1085772 external/wpt/css/css-pseudo/first-line-opacity-001.html [ Failure ]
 
-# Disabling test to checkin associated frontend changes on DevTools
-crbug.com/1136655 http/tests/devtools/throttling/mobile-throttling.js [ Failure Pass Timeout ]
-
 # motion-1 issues
 crbug.com/641245 external/wpt/css/motion/offset-path-ray-002.html [ Failure ]
 crbug.com/641245 external/wpt/css/motion/offset-path-ray-003.html [ Failure ]