Bug 989403 - Invalidate inactive layer's region correctly in the presence of a resolution. r=roc

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extra : rebase_source : 899c27b493e1aabd65d512154e7ac6f345fdf6e1
Bug 1044408: enable crashing all GMP plugins on a pref strobe r=cpearce,ted
Bug 1037424 - Part 1: Implement prefs-based screenshare domain whitelist in MediaManager. r=mt