D16941: Fix inconsistent viewport positioning in PageView

[Andrew Crouthamel]

acrouthamel added a reviewer: Okular.

REPOSITORY
  R223 Okular

REVISION DETAIL
  https://phabricator.kde.org/D16941

To: tobiasdeiminger, #okular
Cc: sander, aacid, okular-devel, ngraham