Merge pull request #11705 from davidflanagan/bug903944-2

Bug 903944 - workaround gecko crash in bug 908432 r=therold(cherry picked from commit fb0d080f53f4248cb2dd0ac4ed07f90b4984e74f)

Conflicts:

	shared/js/media/media_frame.js
Merge pull request #11734 from davidflanagan/bug903944-v1-train

Bug903944 v1 train