Revert "Make Panel scroll the correct div (#12736)"

Revert "Make Panel scroll the correct div (#12736)"
Revert "Reverted change in how hack works (#12727, #12736)"
Revert "Fixes the handling of the scroll position of a Window (#12736)"
Revert "Recovering scroll position after regression problems. (#12727)"
Revert "Ticket #12727 - Panels get unnecessary scroll bars in WebKit when content is 100% wide."

This reverts commit 6a63d12afc5a4bf3971dd016f8e2761cd27bcc74.
This reverts commit c48c94dc23da22b6d885c69b0bc697257f9dbf11.
This reverts commit 017bd0684c7d6c8475c8b43514e6f3998095c8d6.
This reverts commit 51a46a038fe0353f4babfd8218153eb68e2602ca.
This reverts commit ab5b20cf502f99944c82f619ffef387f0525e8ba.

Test cases were left as-is as the issue (#12736) still needs a workaround

Change-Id: I0b6c2afb4a9be8629f2a8f880a8ae8d0a6d5088f