EFL and QT use applyPageScaleInCompositor like chromium, so EFL and QT must shrink the visible content rect in ScrollView for fixed layout like Bug 107424.
EFL and QT already shrink the visible content rect. In detail, m_fixedVisibleContentRect in ScrollView is already shrinked because PageViewportController::syncVisibleContents() calls DrawingArea::setVisibleContentsRect() with shrinked visibleContentsRect.