Temporarily remove webrtc.audio.
Temporarily remove webrtc.audio.

Due to bug 568333, having a benchmark with @Disabled('all') disabled all
sibling classes. This CL can be reverted when bug 568333 is fixed.

Also, webrtc.audio can be added back, not disabled, when bug 468732
is fixed.

BUG=568333
CQ_EXTRA_TRYBOTS=tryserver.chromium.perf:linux_perf_bisect;tryserver.chromium.perf:mac_10_10_perf_bisect;tryserver.chromium.perf:win_perf_bisect

Review URL: https://codereview.chromium.org/1544573002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#367400}

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