Revert "APSTUD-7636 Cannot show preview (embedded WebKit browser)"

This reverts commit 16ec609c09b245c4b0c94bffbe982df660a66641.
Revert "APSTUD-7636 Cannot show preview (embedded WebKit browser)"

This reverts commit 65ac87292d991f11a8afaf76b45783dc9620437d.
Fixed APSTUD-7825: show preview window loaded flush right.