Reviewed by Simon Hausmann.

When we apply the transform of the parent painter to the painter of
the transparency layer, we adopt its coordinate system, thus offset
should not be in page coordinates, but in the coordinate system of
the parent painter.

* platform/graphics/qt/GraphicsContextQt.cpp:
(WebCore::TransparencyLayer::TransparencyLayer):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@59837 268f45cc-cd09-0410-ab3c-d52691b4dbfc