Re-enable a previously disabled test

The test was disabled in https://crrev.com/c/2403560 and it can be
enabled now becaused DevTools has been rolled.

Bug: 1125357
Change-Id: Ic09d1bc8437ad6c1a5efc80a58867fee79eb956b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2413250Reviewed-by: Mathias Bynens <mathias@chromium.org>
Commit-Queue: Alex Rudenko <alexrudenko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807364}

third_party/blink/web_tests/TestExpectations

@@ -1798,7 +1798,6 @@ crbug.com/1075869 http/tests/devtools/elements/styles-1/color-swatch.js [ Pass F
 crbug.com/1075869 http/tests/devtools/elements/styles-3/spectrum.js [ Pass Failure ]
 crbug.com/1075869 http/tests/devtools/elements/styles-4/styles-invalid-color-values.js [ Pass Failure ]
 crbug.com/1075869 http/tests/devtools/extensions/extensions-timeline-api.js [ Pass Failure Timeout ]
-crbug.com/1125357 http/tests/devtools/elements/styles-3/styles-cssom-important-property.js [ Pass Failure ]
 
 # On these platforms (all but Android) media tests don't currently use gpu-accelerated (proprietary) codecs, so no
 # benefit to running them again with gpu acceleration enabled.