Bug 1073039. Change uniform workaround to use raw gl. r=mstange

Bug 1073036 is changing the way we track shader state. Making
this use raw gl instead of Activate() allows CompositorOGL
to remain ignorant of it.

--HG--
extra : rebase_source : ed7e98b35b3fb7c7ea902ee921e09f9cf620b245