Re-enable a devtools web test

This test was disabled temporarily to land a devtools-frontend change.
This new CL updates the test so it passes with the frontend change and
re-enables it.

Frontend change was:
https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2817904/

Bug: 1197542
Change-Id: Ie7d37924c36a519a482e1670e3ea8e6c55aee66d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2826130
Reviewed-by: Alex Rudenko <alexrudenko@chromium.org>
Commit-Queue: Patrick Brosset <patrick.brosset@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#872379}

third_party/blink/web_tests/TestExpectations

@@ -6752,6 +6752,3 @@ crbug.com/1196201 fast/events/mouse-event-source-device-event-sender.html [ Pass
 # Sheriff 2021-04-13
 crbug.com/1198515 [ Mac ] external/wpt/web-animations/timing-model/animations/playing-an-animation.html [ Pass Failure ]
 crbug.com/1198698 external/wpt/clear-site-data/storage.https.html [ Pass Timeout ]
-
-# Temporarily disabled to land a devtools-frontend change.
-crbug.com/1197542 http/tests/devtools/elements/styles-2/metrics-box-sizing.js [ Pass Failure ]

third_party/blink/web_tests/http/tests/devtools/elements/styles-2/metrics-box-sizing.js

@@ -73,7 +73,7 @@
         'padding: ' + getChildTextByClassName(paddingElement, 'top') + ' ' +
         getChildTextByClassName(paddingElement, 'right') + ' ' + getChildTextByClassName(paddingElement, 'bottom') +
         ' ' + getChildTextByClassName(paddingElement, 'left'));
-    TestRunner.addResult('content: ' + contentDimensions[0].textContent + ' x ' + contentDimensions[1].textContent);
+    TestRunner.addResult('content: ' + contentDimensions[0].textContent + ' x ' + contentDimensions[2].textContent);
   }
 
   function createDoubleClickEvent() {