LayoutTests: remove outdated test expectation (introduced for V8 roll).

R=machenbach@chromium.org
BUG=592409

Review-Url: https://codereview.chromium.org/2084493002
Cr-Commit-Position: refs/heads/master@{#400637}

third_party/WebKit/LayoutTests/TestExpectations

@@ -1377,8 +1377,6 @@ crbug.com/591902 [ Linux Mac10.10 Mac10.11 Retina ] http/tests/security/contentT
 
 crbug.com/592185 fast/repaint/fixed-right-in-page-scale.html [ Failure Pass ]
 
-crbug.com/592409 inspector-protocol/debugger/stepping-with-blackboxed-ranges.html [ Failure ]
-
 crbug.com/594595 [ Linux ] http/tests/security/mixedContent/websocket/insecure-websocket-in-secure-page-worker-allowed.html [ Timeout Pass ]
 
 crbug.com/617799 crbug.com/619630 compositing/squashing/iframe-inside-squashed-layer.html [ NeedsRebaseline ]