Revert "[css-flexbox] Make sure to layout overflow:auto elements"

This reverts commit 408ad4e0f177e8f6116963387576edd3f33c6e45.

Caused performance regressions. But I'm keeping the test, marking
it as failure for now.

Bug: 979363, 972227
Change-Id: I984c6be4501a6eb00dff56c1a3322860023367d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1689332
Reviewed-by: Emil A Eklund <eae@chromium.org>
Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675410}
2 files changed