If JavaScript shows a dialog, cause the page to lose fullscreen.

BUG=670135, 550017, 726761, 728276

Review-Url: https://codereview.chromium.org/2906133004
Cr-Commit-Position: refs/heads/master@{#478884}
void WebContentsImpl::OnAudioStateChanged(bool is_audible) {
  SendPageMessage(new PageMsg_AudioStateChanged(MSG_ROUTING_NONE, is_audible));

  NotifyNavigationStateChanged(INVALIDATE_TYPE_TAB);
}

void WebContentsImpl::OnAudioStateChanged(bool is_audible) {
  SendPageMessage(new PageMsg_AudioStateChanged(MSG_ROUTING_NONE, is_audible));

  NotifyNavigationStateChanged(INVALIDATE_TYPE_TAB);
}
