Bug 996186 - Customize mode briefly makes titlebar transparent during transition. r=Gijs, a=sylvestre

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extra : transplant_source : %BB%A2%1D%FB%D3%817%A8%0D%11%8D%C1%E3%A7%AB%D81vXx
Bug 995164 - registerArea should work correctly with customize mode, r=mconley, a=sylvestre

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extra : transplant_source : %F43%8B%EBn%12A%DD%5D%D1%25W%D5y%19N%E2%E2%1C%DF
Bug 987792 - increase panel buttons' labels' clip rect height, r=jaws, a=sylvestre

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extra : transplant_source : %02cH%F7JYa%14%B2%B9%7C%19%F6%7B%D2%9B%28G%3E1
Bug 987067 - use different selector on Windows/Linux than on OS X for background tab clipping for pointer events, r=dao,MattN, a=sylvestre

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extra : transplant_source : %87%A8%E8%C2K%F9%ACX%DF%CA%02%CB%BB%A1%3C%DD%DAYr%8B