Bug 787619 shows a case where a media player script expects the plugin to block clicks and because the click-to-play placeholder does not the script thinks you're still seeing the preview image and recreates the plugin.
Created attachment 673569 [details] [diff] [review]
Comment on attachment 673569 [details] [diff] [review]
[Approval Request Comment]
Regression caused by (bug #):
User impact if declined: Unable to click-to-play some plugins
Testing completed (on m-c, etc.): Similar patch applied to Firefox
Risk to taking this patch (and alternatives if risky): Very low
String changes made by this patch: None
Pushed comm-central changeset cb0c2eab4492.