Fix white line at the bottom during slideshow.
Fix white line at the bottom during slideshow.

This partially reverts 0a5b49e7199198974113dc2e8b68257b881fb9fb,
which affects _all_ Impress views, including slideshow.

Change-Id: I297c09bc3c6466e83acfd423fc24d75da9df2833

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core