Add test suppression for webaudio/sine-oscillator.html.

TBR=yhirano
BUG=431688

Review URL: https://codereview.chromium.org/713943002

git-svn-id: svn://svn.chromium.org/blink/trunk@185055 bbb929c8-8fbe-4397-9dbb-9b2b20218538