Bug 848644 - Do not flush when determining if a node is preformatted or not; r=bzbarsky a=dveditz

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extra : transplant_source : %CD%DF_u%84%3F%1B%2Bw%40%D6%1A%CE%87%01%3C%BC%C9%14%E9
Bug 846334 - reduce flickering of social panels.  r=jaws, a=bajaj