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YouTube Wait for Me - Pause and Start Player in Background Tabs

Pause the video in YouTube tabs opened in the background, play on activation 2016-08-18 (I know, it doesn't pause fast enough)

ئاپتورى
Jefferson Scher
بۈگۈن قاچىلانغىنى
0
جەمئىي قاچىلانغىنى
144
باھا نومۇرى
1 0 0
نەشرى
0.7
قۇرۇلغان ۋاقتى
2016-08-19
يېڭىلانغان ۋاقتى
2016-08-19
ئىجازەتنامىسى
BSD 3-clause
قوللايدىغىنى

Inspired by this thread on Mozilla Support: https://support.mozilla.org/questions/1135383

Note: Does not work if the media.autoplay.enabled has been switched to false (with that setting, Firefox requires that you manually click pause and then click play)