Mark webaudio/osc-sine-sweep-snr.html as failing on win, flaky on linux
Mark webaudio/osc-sine-sweep-snr.html as failing on win, flaky on linux

TBR=pdr
BUG=

Review URL: https://codereview.chromium.org/913673002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@189889 bbb929c8-8fbe-4397-9dbb-9b2b20218538

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk