Remove a timeout expectation for webaudio IDL test

The test doesn't seem to timeout. It was marked so due to flakes during
an import.

TBR=rtoy

Bug: 846188
Change-Id: I06cdd58043005394fd39a4237dd4f5b6db237733
Reviewed-on: https://chromium-review.googlesource.com/1072905Reviewed-by: Robert Ma <robertma@chromium.org>
Commit-Queue: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561877}

third_party/WebKit/LayoutTests/TestExpectations

@@ -2899,7 +2899,6 @@ crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftest
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/shapes1/shape-outside-circle-043.html [ Failure ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/shapes1/shape-outside-border-box-border-radius-003.html [ Failure ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/shapes1/shape-outside-border-box-border-radius-008.html [ Failure ]
-crbug.com/626703 [ Mac10.12 ] external/wpt/webaudio/idlharness.https.html [ Timeout ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/shapes1/shape-outside-circle-054.html [ Failure ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/shapes1/shape-outside-border-box-border-radius-004.html [ Failure ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/shapes1/shape-outside-circle-048.html [ Failure ]