Switching AudioOutputAuthorizationHandler from using AudioManager interface to AudioSystem one.

BUG=672468
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2692203003
Cr-Commit-Position: refs/heads/master@{#450939}
void AudioRendererHost::OnSetVolume(int stream_id, double volume) {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);

  AudioOutputDelegate* delegate = LookupById(stream_id);
  if (!delegate) {
    SendErrorMessage(stream_id);
    return;
  }

  if (volume < 0 || volume > 1.0)
    return;
  delegate->OnSetVolume(volume);
}

void AudioRendererHost::OnSetVolume(int stream_id, double volume) {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);

  AudioOutputDelegate* delegate = LookupById(stream_id);
  if (!delegate) {
    SendErrorMessage(stream_id);
    return;
  }

  if (volume < 0 || volume > 1.0)
    return;
  delegate->OnSetVolume(volume);
}
