Enable event-listener-breakpoints-webaudio.js test

This is a follow-up CL of
https://chromium-review.googlesource.com/c/chromium/src/+/1115516.

TBR=rtoy@

Bug: 856215
Change-Id: Ib2836d831968795eac6a95eae6148469af69d15d
Reviewed-on: https://chromium-review.googlesource.com/1121209Reviewed-by: Hongchan Choi <hongchan@chromium.org>
Commit-Queue: Hongchan Choi <hongchan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571907}

third_party/WebKit/LayoutTests/TestExpectations

@@ -4730,7 +4730,6 @@ crbug.com/856601 [ Linux ] virtual/feature-policy-permissions/external/wpt/media
 crbug.com/856955 [ Win10 Linux ] inspector-protocol/animation/animation-multiple-frames.js [ Failure Pass ]
 
 # Sheriff 2018-06-28
-crbug.com/857414 [ Win Mac10.10 Mac10.11 ] http/tests/devtools/sources/debugger-breakpoints/event-listener-breakpoints-webaudio.js [ Pass Timeout ]
 crbug.com/857520 [ Mac Win ] external/wpt/accelerometer/Accelerometer-iframe-access.https.html [ Failure ]
 
 # Sheriff 2018-06-29