Re-enable SoftContextMenu layout test.

It was disabled to allow a DevTools Frontend CL to land, but it should
now be able to run again. I thought the test would need updating given
the changes in the source file, but it doesn't. There was a legitimate
bug in the source CL (which has since been fixed) which I mistakenly
took to mean I needed to disable the test before my frontend change
could land.

Fixed: 1150854
Change-Id: I672b336941e5f9a797a09d3139af1ea61f516ad3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2558338
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
Auto-Submit: Jack Franklin <jacktfranklin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830995}

third_party/blink/web_tests/TestExpectations

@@ -6013,9 +6013,6 @@ crbug.com/1149987 external/wpt/websockets/Create-blocked-port.any.worker.html [
 crbug.com/1150518 [ Win ] virtual/gpu/fast/canvas/canvas-composite-shadow.html [ Pass Timeout ]
 crbug.com/1150475 fast/dom/open-and-close-by-DOM.html [ Pass Failure ]
 
-# Skip to land change in frontend (https://crrev.com/c/2550061) before this layout test can be updated
-crbug.com/1150854 http/tests/devtools/unit/soft-context-menu.js [ Skip ]
-
 #Sheriff 2020-11-23
 crbug.com/1151861 external/wpt/workers/semantics/multiple-workers/003.html [ Timeout Crash ]
 crbug.com/1152088 [ Mac10.13 Debug ] fast/dom/cssTarget-crash.html [ Pass Timeout ]